I hatch in the schools, but I consider it more volunteer work for fun. Allergies are a big consideration, so a quick letter to parents to find out if there might be a problem is always wise. Most of the schools have their own incubators, so I just sell them the eggs and help them out. I also go in a few times:
1. deliver the eggs, check or set up incubator, show kids the colors of diff eggshells
2. visit with a hen for kids to pet, talk about basic chicken vocab, & candle to show development (bring clear eggs to show differences)
3. stop by sometime on hatch day
4. if they have no use for the chicks, I take them back here & sell them.
Most teachers give me about $20-25 for the eggs, plus all the cute little thank you cards, photos, etc. Then I get back a little money for whatever price I sell the chicks. That price depends on what purebreds or mixes hatch. The thermometers, shavings, feed, and other brooder supplies all come from the teachers, but I'm nearby in case they run out & need a cup of feed or have a weak chick in need of TLC.
In all the schools, the day when I bring in the hen is a BIG deal. Two schools call it an in-school field trip. They set up a few rows of chairs along the back & invite the parents to attend.