Did you know that there’s a way to check if an egg is fertile or not? It’s called egg candling and although animal keepers rarely use a candle to check the fertility of eggs these days, it’s fascinating to watch. Instead of a candle, keepers usually use a special torch that allows you to see inside the egg. Â Most candling happens with bird eggs but I have been lucky enough to see fresh water crocodile eggs being candled too.
Many of us don’t have access to fertile eggs to let our children experience egg candling first hand though (including me) so I decided to create a fun egg candling activity.
What you’ll need:
- Eggs (please support free range chickens)
- Needle or pin
- Masking tape
- Printable animal silhouette and quiz (below)
- Scissors
- Glue stick
- Torch
Egg candling activity: How to
1. Â Create a small hole in the side of an egg by pushing a needle into the egg.
2. Â Using the needle, work the hole into a bigger hole until you can get your finger all the way through the hole.
3. Â Clean the egg contents out (use them in wildlife pikelets perhaps) and let it sit and dry. The inside of the egg must be dry before you do the next step.
4. Â Print the animal silhouette and quiz sheet below
 5. Cut out an animal silhouette you’d like to use inside the egg. Use a glue stick to glue over the top of the animal silhouette cut out. You’ll be tucking the picture into the hole and sticking it to the inside of the egg.
5. Stick the picture inside the egg. Make sure the picture sticks to the egg quite well by smoothing it with the tips of your fingers.
6. Close the egg’s hole using some pieces of masking tape.
7. Paint your eggs but don’t go too heavy on the paint or it might spoil seeing the silhouette inside.
8. Move the torch around to get a good light going through the egg. I found putting the torch up to the masking tape that covers the hole was the best place to shine the torch. Such a fun egg candling activity!
To play the game
For young children: Don’t use the quiz cards. Instead, let them light up the eggs  in a dark room and guess the animal inside. Then ask them these questions about the animal:
- What does this animal eat?
- What noise does this animal make?
- Where does this animal live?
For Older Children:Â Set up a place in a dark spot. Let your child explore the eggs and use the torch to guess the animals inside.
Then, give your child the the quiz cards and ask them to place the quiz cards with the correct animal.
As an added surprise. Why not hide a little plastic animal inside an egg for once your child has finished the activity? Kids do love cracking eggs!
Have you ever heard of candling eggs?
We have done this before, with a light behind chicken eggs – to see if they’re fertilised!
Soooo very exciting for both the kids AND the grown ups!
I’ve never thought of doing it with eggs of other animals Penny. What’s your advice there? Would it effect the eggs if we found some (eg gecko / spider) and tried this with a torch?
I LOVE your creative idea! Not having to interfere with real animal eggs at all makes it safer and we get a perfect result every time! You have so much here to help our kids interact with and enjoy nature. Thank you x
Aleta, I was lucky enough to see fresh water crocodile eggs being candled once. That was pretty cool. You just have to be more careful with reptile eggs and keep them upright and place them back in the exact same way or the baby inside will drown. I’d love to candle a turtle egg. Imagine! I can’t believe I forgot to put that one on the printable!
I’ve never tried candling a spider egg sack either but a huntsman egg sag is slightly translucent so I couldn’t see why not. You’d have to get past the maternal mum first though!
This is WAY cool! Pinning it.
This is INSANELY awesome Penny! What an amazing and interesting life you have working at the zoo. Thanks for the wonderful printable that goes with this too.
So cool Penny! My kids would love this!
What a fabulous idea, Penny, my six year old will love this.