Bring in books and posters about the type of animal you'll be getting. Read books to the class, then explain that this is the type of pet you're going to have. Ask children to make observations and guess what kinds of things you'll need to do to keep the pet safe and healthy. You can also take suggestions for a name, then have the class vote on one.
Set up the pet's cage or bowl. Consult a book about caring for the animal or talk to a pet store worker to choose the correct equipment. The pet's cage should be low enough that students can see it, but high enough that they can't reach the top. This will prevent children from letting the animal out or dropping things into its cage.
Gather children around the cage. Show them how the cage works, then show them the type of food you'll feed your pet. Explain the rules for caring for the pet. For instance, you might be the only one who will feed him or you might choose a different child each day to help.
Children may not remember the rules you have explained, so make signs about caring for the animal. Draw illustrations on each sign, since preschoolers can't yet read. You can make one sign showing how and when to feed the pet. For instance, if he must be fed twice a day, draw a hand pouring food into his cage next to a picture of the school bus arriving. Draw another feeding picture next to a picture of a book. This shows children that the pet needs to be fed right when they arrive at school in the morning, then again during book time. You can also make signs showing children what not to do. For instance, draw a picture of a child banging on the cage. Draw a red "X" through the picture to remind children not to touch the cage.
Place the new pet inside his cage at the end of the day when students are gone. This will give him a chance to get used to his new surroundings before being bombarded with attention from preschoolers. When children come into the classroom the next morning, invite them to quietly walk over and look in the cage. If you're going to take the pet out for children to touch, take two or three children at a time into a quiet corner to pet him and examine him up close.