Sep 22, 2012

Hatch-along with The Chicken Chick: Part 4: Egg Candling

How to Candle Chicken Eggs
Brinsea Ovascope (black) and high-intensity candler (yellow) The Ovascope sits on top of the candler.
Brinsea Ovascope (black) and high-intensity candler (yellow) The Ovascope sits on top of the candler.
So far, we’ve discussed hatching addiction, roosters, broody hens, shipped eggs, caring for hatching eggs, hatchability of eggs and incubator basics. Now we turn to embryo development and candling. It has been seven days since I set the Buff Orpington eggs in the incubator. The temperature has remained a rock-solid 99.8°F, the eggs have been turned every 45 minutes by the automatic turner and I have added water a couple of times as the level in the reservoir dropped. Now the fun begins- it’s time to candle the eggs!
Candling is the term used for shining a light through an eggshell to see what’s happening inside. The reason to candle to see whether the embryo is developing or not; those that are not developing should be removed from the incubator on day 14 (or sooner if they begin to smell bad). There are many reasons an egg could fail to develop or begin developing and stop.
ABOUT CANDLING
Candling is the term used for shining a light through an eggshell to see what’s happening inside. The reason to candle to see whether the embryo is developing or not; those that are not developing should be removed from the incubator on day 14 (or sooner if they begin to smell bad). There are many reasons an egg could fail to develop or begin developing and stop.
Dark brown eggs (eg: Black Copper Marans, Pendesenca, Welsummer) are among the most challenging eggs to candle as the brown pigment is laid in a fairly thick layer on top of the eggshell.
White and light brown eggs are the easiest to candle as there is little to no pigmentation on the eggshell. Pigmentation in blue eggs runs all the way through the shell, making blue eggs a little more difficult to candle than white or light brown eggs. Dark brown eggs (eg: Black Copper Marans, Pendesenca, Welsummer) are among the most challenging eggs to candle as the brown pigment is laid in a fairly thick layer on top of the eggshell. Dark green and olive colored eggs are also very challenging as the blue pigment permeates the shell and the dark brown pigment lies on top of the shell.
Dark green and olive colored eggs are also very challenging as the blue pigment permeates the shell and the dark brown pigment lies on top of the shell.
HOW TO CANDLE
When candling an egg, a light is held up to the wide end of the egg (the air cell end) in order to illuminate the shell’s contents. The darker the eggshell, the brighter the light required to get a good look at what’s going on inside. I have used any number of candling devices from homemade to commercial candlers and can report that, with all except the very darkest eggshells, a good, bright LED flashlight is sufficient. The homemade candlers were worthless and the best commercial candlers are relatively expensive, but effective. 
This is the Brinsea Ovascope with the candling light off.
This is the Brinsea Ovascope with the candling light off.
 The candling light is turned on in this picture.
 The candling light is turned on in this picture.
 The Ovascope cover is closed for best viewing.
 The Ovascope cover is closed for best viewing.
I candle with the Brinsea high intensity Ovascope and while it is a good investment for the hatch-a-holic, the infrequent hatcher will get along just fine with a two dollar flashlight. The other advantage to the high-intensity OvaScope, beyond candling dark eggs better than a flashlight, is that it frees up my hands for taking photos. I always place a towel on the work surface where I will be candling in case I drop an egg so its fall is cushioned. I have broken more eggs during candling than I wish to recall.
Watch the OvaScope IN ACTION with twin embryos on my YouTube channel HERE!

When I candle with a flashlight, I do so at night in a dark room or during the day, in a closet. (yes, I have candled in my pantry)  I grasp the flashlight in my left hand as shown and place the wide end of the egg on top of my index finger and thumb so that no light leaks out from around the egg. Works like a charm.
When I candle with a flashlight, I do so at night in a dark room or during the day, in a closet. (yes, I have candled in my pantry)  I grasp the flashlight in my left hand as shown and place the wide end of the egg on top of my index finger and thumb so that no light leaks out from around the egg. Works like a charm.
When I candle with a flashlight, I do so at night in a dark room or during the day, in a closet. (yes, I have candled in my pantry)  I grasp the flashlight in my left hand as shown and place the wide end of the egg on top of my index finger and thumb so that no light leaks out from around the egg. Works like a charm.
When I candle with a flashlight, I do so at night in a dark room or during the day, in a closet. (yes, I have candled in my pantry)  I grasp the flashlight in my left hand as shown and place the wide end of the egg on top of my index finger and thumb so that no light leaks out from around the egg. Works like a charm.
Twin embryos can be seen developing in this video!
WHAT TO LOOK FOR WHEN CANDLING
1. Embryo development: My blog post on embryo development illustrates with great detail the stages of growth day-by-day as seen from the inside and outside of the egg.

 All eggs will have an oval shadow inside, which is the yolk.
 All eggs will have an oval shadow inside, which is the yolk.
After a minimum of 4 days of incubation, a dark spot inside the yolk should be visible with veins extending out from it in a spider-like formation.
After a minimum of 4 days of incubation, a dark spot inside the yolk should be visible with veins extending out from it in a spider-like formation.
A red ring around the egg indicates embryo death and the egg should be removed from the incubator immediately.
what to look for when candling an egg- blood ring=bacteria
 Always wash hands before candling to avoid contamination. I always SMELL the eggs when candling for signs that the egg has died from bacterial contamination. If a bad egg explodes, it can contaminate and compromise the entire hatch. A bad egg has a distinctive, putrid stench- there's no question when there is a bad egg in the bator. On the days that I don’t candle, I make a point of getting near enough to the incubator to be able to smell any bad eggs at the earliest stage possible. More on bad egg detection and handling here. 
The following photo is a late quitter. It began developing and then died.
The following photo is a late quitter. It began developing and then died.
The following photo is a late quitter. It began developing and then died.
2. Air cell enlargement: Another indication of development is the size of the air cell. All eggs have an air pocket between the two membranes inside the shell. Ideally, it is located at the wide/large end of the egg. When an egg is first collected, the air cell will be small but during incubation, it quickly becomes larger. As the embryo grows, moisture is lost through the cell’s pores, which causes the air cell to increase in size. When I was new to incubating, I would take a pencil and mark the air cells’ positions before I set them in the bator and when I would candle, I would mark the position again. It’s interesting to see how quickly the air cell grows in three weeks.
Another indication of development is the size of the air cell. All eggs have an air pocket between the two membranes inside the shell. Ideally, it is located at the wide/large end of the egg.
I candle much more often than is necessary or recommended. You can see from this picture that there are many pencil lines marking the days on which I candled- that is generally not a good idea. Most incubators are very sensitive to fluctuations in temperature and humidity and too-frequent opening of the incubator can compromise the hatch. A good rule of thumb is to candle at days 7, 14 and 18.
I candle much more often than is necessary or recommended. You can see from this picture that there are many pencil lines marking the days on which I candled- that is generally not a good idea. Most incubators are very sensitive to fluctuations in temperature and humidity and too-frequent opening of the incubator can compromise the hatch. A good rule of thumb is to candle at days 7, 14 and 18.
 These are photos that I took today of my Buff Orpington egglets. The visibility is not what I would ordinarily expect from light brown eggs, but I can tell that all five are developing!
 These are photos that I took today of my Buff Orpington egglets. The visibility is not what I would ordinarily expect from light brown eggs, but I can tell that all five are developing!
 These are photos that I took today of my Buff Orpington egglets. The visibility is not what I would ordinarily expect from light brown eggs, but I can tell that all five are developing!
 These are photos that I took today of my Buff Orpington egglets. The visibility is not what I would ordinarily expect from light brown eggs, but I can tell that all five are developing!
 These are photos that I took today of my Buff Orpington egglets. The visibility is not what I would ordinarily expect from light brown eggs, but I can tell that all five are developing!
 These are photos that I took today of my Buff Orpington egglets. The visibility is not what I would ordinarily expect from light brown eggs, but I can tell that all five are developing!
Kathy Shea Mormino, The Chicken Chick®
 The Chicken Chick is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com

91 comments :

  1. I would love some silkies!
    Vicki Ritchie
    Vritchie@neo.rr.com

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  3. wow! i know who to go to when we start hatching our own eggs! thanks for all the great info.

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  4. My next breed is a Cuckoo Marans! Actually my 5 yr. old "dirt chick" is coming to visit me for 4 days next week so that we can go increase our flock with another 5 babies. Don't know whose is more excited..bought her the Dog & Chicken book and thought the cap would be perfect reward for her hard work.

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  5. This hat is so super cute. We have a new niece or nephew to arrive any day now and this hat would allow me to add my special chicken touch to the new family member!
    There is not one particular breed I'm interested it. We welcome any kind of featherd friend since we have a couple of adopted chickens :)

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  6. Oh my goodness... these pictures are so fantastic!! It makes me even more excited to let my silkie hatch our first eggs in the Spring <3

    My next chicken that will join us is a Black Silkie <3

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  7. I love seeing the embryo pictures. It is so amazing to think that life starts from that tiny white speck on the yolk. I have been having fun teaching my kids about the internal structure of living creatures. The complexity is astounding. To think that it starts from one cell is really mind blowing! Anyway, if I could add one new breed to my flock it would be Lavender Orphingtons. I am in love with the color and the Orphintons are so sweet - I think the kids would love them.

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  8. I WANT THAT HATTTTT!!!!!!!! Id love to have it as my next breed!!! ;))))

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  9. Mary Hartwell9/22/12, 7:29 PM

    I have never hatched, so haven't gotten to candle....very informative article though! And the next type of chicken I would like would be a Silkie!!! I absolutely adore them!

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  10. im wanting to get Frizzle bantams next!!

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  11. Frizzle bantams next!! Terah Life

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  12. Don't tell Fiddle or Fahgel but I want more ORPINGTON'S!. Blue, Buff, it doesn't matter! Beatrice has me wrapped around her funny bent toe!

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  13. ORPINGTON'S! Blue, Bull, I don't care! Beatrice has me wrapped around her funny bent toe!

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  14. Anne Guffey9/22/12, 7:41 PM

    Buff Orpingtons are next!

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  15. I LOVE candeling-- totally addicted! I would love to add Old English Game bantams to my flock! I think they are adorable! That... or maybe some marans for even darker egg layers! :)

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  16. I want to add buckeyes... Plus some Ameracauna, plus some.... I could go one all night.... Love the hat... My girls would look absolutely precious sporting this hat!!!

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  17. This is fascinating. I can't wait to try hatching eggs. None of my hens are broody. For the contest...Partridge Pendesenca, Wellsummer,Sicilian Buttercup.

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  18. I would like to add easter eggers to my flock!! :) Kara Steele

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  19. I would love to add some bantams or Easter Eggers to my flock

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  20. Hi Kathy,
    I'm commenting here for the Chicken Hat give-a-way because the link above won't allow me to comment. I also commented under the photo on Facebook. I would like to add a Columbian Plymouth Rock Bantam hen to my flock. I saw one at our local fair and fell madly in love !!! Thanks, Karen

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  21. i use my cell phone to candle my eggs an it works great an my granddaughter would love this hand made hat she loved her splash chicken she is 3 yrs old

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  22. Another informative post! Thank you so much. I am hoping to fing a mate for my male Chinese goose, Charlie. As for chickens, I am looking to add Blue Laced Red Wyandottes to the farm. The color combination is beautiful.

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  23. I really would like to add Welsummers and California Whites, Maybe a Coppper Maran to round egg my egg colors.

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  24. Buff orpingtons next.

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  25. Oddly enough, we don't have any buff orps. I'd love to add those to our flock of weirdness ;)

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  26. Just bought black cooper Maron eggs to hatch!!!!!

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  27. (I already subscribe..LOL)

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  28. I would like a Welsumner or Maran. I would also like "Olive Eggers" but technically, that is not a breed.

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  29. I would like to add easter eggers to my flock! :) I hope I did this right! lol

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  30. I want to add silkies but my boyfriend doesn't .. any help convincing???

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    Replies
    1. Yes, just BUY the baby chicks. Nobody can resist fluffy butts. Nobody. ;)

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  31. kirsty wilson9/22/12, 8:17 PM

    really love that hat! my next breed i want are the aracuna breed!

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  32. Really want to get a buff brahma

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  33. The next breed of chicken I would like would be some Delawares.

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  34. I'd love to have any breed, as my Husband won't let me have chickens:( just wait till he is gone!!!!:)
    j63pup at yahoo.com

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  35. I would love to add some Serama's to my flock next year, but I have some work to do first. I'd love to have one of each kind! :)

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  36. There are so many breeds I want, it's hard to pick just one but if I HAD to it would be cochins. I love their little fluffy butts!

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  37. I think I would like to add either an olive egger or a marans. I love the color of their eggs!

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  38. I would love to add a Black Copper Maran or Blue Ameraucana to our flock. Have you ever purchased hatching eggs and allowed a broody hen without a Rooster to become a surrogate mommy? My sweet 2 1/2 year old would love to wear this sweet hat while hanging out with our flock. Love your site! Thank-you!

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    1. I actually have THREE broody hens sitting on eggs that were shipped to me!

      Congratulations Aimee, you have won the chicken hat! Please email me at Kathy@The-Chicken-Chick.com with your mailing address and your color preference (white or cranberry). :)

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    2. Oh! Thank-you, thank-you, Thank-you! You're a fabulous chicken resource. :-)

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  39. I'm currently at my maximum for chicken breeds, but if I could choose a new breed it would be Swedish Flower Hens!

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  40. My latest fantasy is a lavender orp!

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  41. Ruthmary Hunt9/22/12, 9:09 PM

    Would LOVE to win this hat!!! We have Bantams...about 150 or so...Plan on getting a flock of bigger chickens next spring...We raise American Giant Homer pigeons and we candle our eggs using the lift lights that have 60 watt bulbs ...flashlight is good but lights are better!!

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  42. Nancy Whitesell9/22/12, 9:11 PM

    I definateyl would love to have some silkies.

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  43. Baawk need hat to send to new Granddaughter in Korea!

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  44. I'd love to add some black coppers marons or orps. I'm looking for some good layers and nice egg colors for my egg selling...what are your suggestions? I'm going to get some silkies too just cuz they are gorgeous and there's no better bator than momma! Great hat! Lexylvt@yahoo.com

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    1. I have Black Copper Marans and they are beautiful birds, you just have to be careful about where you buy them. A hatchery will never produce chickens that lay really dark brown eggs.

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  45. Something with Funky Feathers like a Silkie, Frizzle, or Polish would be my next choice for a chicken.
    I Love the hat. Do you crochet too?

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    1. I don't crochet, Cheryl. My mom makes the chicken hats. :)

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  46. I would love some silkies or Wyandottes!

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  47. Love the hat. If I could add more... I would want polish, frizzle or lavender orpingtons.

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  48. Love the hat. I would add frizzles, lavender orps or polish.

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  49. Next on my wish list is lvender orps and blue and black morans! Tried hatching all 3 breeds, but not a singalong one hatched...gonna try again in the spring!

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  50. I have a little friend who loves my chickens. She would be thrilled if she could have a hat like that!

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  51. I would love some pekin bantams next!...Rene

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  52. Im Hatching out true Araucana in a few weeks
    Theresa H.
    hennesseyt3@yahoo.com

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  53. I would love to win that hat for my great niece. She loves chickens !!!

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  54. If an egg is infertile or a quitter under a broody, I assume she'll know and somehow stop sitting on the egg? Have you had this happen? Thanks!

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  55. I think I need one of those HENbags. Gorgeous.
    Love your blog. Great information and so stimulating. Thank you!

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  56. Its only been 2 days since I put my egg in the incubator but I went ahead and candled it and I saw a dark spot but the egg is porus I didnt smell anything though but I dont know if the egg is bad...any suggestions?

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  57. Audrey Siebert4/11/13, 3:29 PM

    Wanted to let you know I read this post about 20 bazillion times before I candled my FIRST hatchlings!!! I'm so excited in about 2 weeks I SHOULD have babies!!!!

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  58. Kathy, you said we could enter everyday but it will not allow that. It says, "this address has already been entered."

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  59. Beth Burnham4/14/13, 12:03 PM

    Is this a contest that you can only enter once? Because the entry form did come up but when I submitted it said it has already been enter. Do I have the most trouble of ANYONE??? I love this article. I love candling and I have to make myself stay away!!

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  60. I am not seeing a spot to enter the drawing. Am I missing something?

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  61. Teresa Cutrell4/14/13, 12:18 PM

    I cannot see the entry form. Please help.

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  62. Teresa Cutrell4/14/13, 12:26 PM

    I am constantly reading different blogs on here....in fact I am at this moment going to go and reread how to may ACV. Great information.

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  63. TheChickenChick4/14/13, 7:46 PM

    I fixed the setting, Barbara. Sorry! Please try again.

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  64. TheChickenChick4/14/13, 7:47 PM

    The email entry option was off, but I fixed it. You do have to wait 24 hours in between entries though.

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  65. TheChickenChick4/14/13, 7:48 PM

    Sherry, try the LOGIN with Facebook option.

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  66. Audrey Siebert4/23/13, 3:22 PM

    Out of 11 eggs (that made it from the 19 I put in the incubator) 2 have pipped as of 1pm....I'm so excited & hoping they don't decide to fully hatch while we are in town this evening!

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  67. Trina Foster12/18/13, 8:26 PM

    💚❤️💚Wow! I Loved learning about this❤️💚❤️

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  68. Gloria Todd Twiggs4/7/14, 2:18 PM

    This is so interesting as this is the 7th day that Lucy is setting. She only gets off thee nest once a day in the morning. Should I wait until tomorrow or can I do it during the day or should I wait until tonight. This is my first experience and since there are a dozen eggs under the little Bantam hen, I am sure that it is hard for her to keep them all warmed.

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  69. TheChickenChick4/7/14, 2:54 PM

    Should you wait to do what, Gloria?

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  70. Gloria Todd Twiggs4/7/14, 6:23 PM

    Should I wait until she is off the nest to test the eggs as there are a dozen under the Little Bantam. She is only leaving the nest in the morning. If I can test the eggs, I could remove the bad ones.

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  71. TheChickenChick4/7/14, 7:53 PM

    I do it after dark.

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  72. Deborah Foti5/2/14, 9:54 PM

    Oh loved this post. I'm new to chickens and I'm just living ur information thank you so much.

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  73. I found your site last night & love it. I was watching the live feed, of the chickens hatching but can not find it today. Could you please post where to find it, thanks!!

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  74. Sure, here you go, Erika: http://www.ustream.tv/user/TheChickenChick

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  75. Help! We have Three brooding hens for the first time.... ( we have always gotten either pullets or chicks from a breeder) So since we don't have a rooster anymore my friend gave us 9 of their probably fertilized eggs to try. The Girls have been pretty faithfully sitting and last friday was day 21. One Chick was hatch ( yea! happy day!) and one tried to hatch out but died trying... but none of the others have hatched
    We pitched two yesterday because they were stincky. I tried candling out of desperation with my husbands spot light and they were all dark with a air pocket. Are they rotten or.. How long do we let them sit?

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  76. It's probably too late now. I'd probably candle one last time and if no movement is seen, open the eggs to find out what went on in there.

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  77. no more chicks. Two of the hens ( the one who hatched the chick and another of the sitters were fighting over the chick. they have decided to share in the raising, but they are feeding it big chicken food even though I have put out a chick feeder with medicated chick food in it. I think she is eating both. Will the laying mash hurt the chick? The third hen who was broody took quite a while to get of any eggs she could find. She looks better today her comb is back to being red. How oft do hens raise a clutch? Should I be looking for a rooster soon or not till next spring.

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  78. Put out unmedicated starter for ALL of the chickens, the chicks cannot eat layer feed.

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  79. Thank so much Kathy! We started some Gold Laced Wyandotte eggs from our hens 7 days ago in our mini advance. Upon candling them last night, all 7 looked good to go - with one embryo even wiggling!

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  80. Kathrine Smith11/16/14, 5:26 PM

    I need help please. My oldest unplugged my incubator yesterday around 4/5pm thinking it was the computer and I only just found out at 7:30am I have plugged it back in now but worried they won't live it's 2.5 hours from being exactly 4 days since they went into to the hatchery. Ps I live in Ayr North Queensland Australia and the temp got down to 24degrees or 75.2 for the USA people.

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  81. The only thing you can do is candle the eggs in a couple of days to see whether they have continued to develop or not. It seems highly unlikely that any will have survived that, but you never know.

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  82. Kathrine Smith11/16/14, 10:47 PM

    Thanks for the help and that's what I was afraid off ;(

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  83. Kathrine Smith11/19/14, 7:18 AM

    Just a quick update I think 3 out of 11 are ok as they look like the photo above (5th one up from the bottom) but 1 is defiantly gone as it had the blood ring

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