One of my all-time favorite science units is the chick life cycle. I love giving my students the opportunity to watch the chick develop inside the egg, hatch, and grow! The chick life cycle is always a student favorite, and one they remember for the rest of their lives. In fact, I still fondly remember studying the chick life cycle when I was in kindergarten! So, what do I teach my students in our chick life cycle unit?
Inside the egg
I always start the chick life cycle unit with teaching my students about what is going on inside the egg. I show them diagrams and pictures, but it is always more exciting to see inside the egg for themselves. After learning the different parts of the egg and labeling them, like in this example, I meet with the students in small groups to see inside the egg. I buy grocery store eggs for this activity and pass around the egg to let them feel the hard shell. After observing the shell, I crack it open carefully and drop the insides into a bowl. When you do this, you can see the albumen, chalaza, yolk, and if you look really carefully, you can see the germinal disc!
Candling the Egg
The second way that I have my students observe the inside of the egg is by candling the egg. You can buy a special candling tool, or a regular flashlight should work as well. Have students gather around you in small groups and turn off the lights so it is as dark in the room or area as possible. I even once took some groups into the classroom bathroom so that we can have it completely dark. Another time, I put a big sweatshirt over the group and we huddled underneath it. You want it to be dark, ok? So then, you push the candling tool under the egg and move it around the egg. As you move it around, you can see the veins clearly and the air pockets, because they turn dark whereas the yolk and albumen light up. What you want to look for is a moving dark circle. Its easiest to see the eyes of the growing chick embryo first. Then you can see the faint outline of the chick. If you don’t see any, then there may not be a chick growing inside, another important lesson for students to learn.
You can candle eggs whenever you like, but there are a few things to consider. Growing chick egg should not be out of the warmth of the incubator for too long. I took about 3 or 4 at a time to show each group and then put them back and took new ones out for the next group. I only candled twice while the chicks were growing because there isn’t a ton of changes you can see from day to day and the chicks really do need time in the incubator to grow.
Observing the hatching process
After 21 days of growing inside the eggs, the chicks are ready to hatch. Hatching day is the best day of the chick life cycle, in my opinion. You can start to look for little pecks at the egg to see chicks trying to hatch out, but usually, by the time you come to school, there is already one chick out of the egg or almost out of the egg, with others soon to follow. Children love being able to come up and check on the eggs throughout the day. If you can, leave the document camera or your phone to easily showcase the hatching to the whole class. Sometimes a chick does not finish hatching. This is unfortunately a normal part of the chick life cycle. You are not supposed to help any chick that gets stuck in the hatching process, as this usually means they will not be strong enough to live. So even if you see eggs starting to hatch, it doesn’t necessarily mean you will have that many chicks fully hatch.
Observing baby chicks
You are supposed to leave the newly hatched chicks in the incubator for 24 hours, so they dry out and stay warm. This means that on day 20, right before hatching day, you should take the eggs out of the egg turners and add in a bowl of water and chick food for the new chicks. Once the chicks stop looking wet, you take them out and put them in the brooder. The children can help create the brooder with you a day or two before the hatching begins. You’ll want lots of newspapers, a warming lamp, and bowls for food and water. I now use a plastic container because then the children can easily observe what is happening with the chicks. I have also found that their sides are bigger so the chicks can’t jump out (that has happened to me with a cardboard box before!
Give the children lots of time to observe the chicks as they grow. I love using these observation pages to help the children think about their observations in terms of their senses. What do they hear, see, smell, etc. Every so often, we put a bunch of newspaper down on the rug and the children help build some walls with our class blocks. Then everyone sits around the circle and can easily observe the chicks walk around, drink water, and eat. The children always love being able to watch the chicks!
The chick life cycle is one of my most favorite units of the whole year, and it’s one I still remember from when I was in kindergarten! Children love to observe the inside of the chick egg, the hatching process, and the chicks! Have you tried a chick life cycle unit before? What was your favorite part? Let me know in the comments!