How to Care for Outside Caterpillars

Find caterpillars outside on leaves or branches. Some good host plants where you can find caterpillars include Milkweed, Spicebush, Paw-paw and Parsley. Remove the stem that the caterpillar is on and place it in a container. Do not pick up a caterpillar with your fingers.

Keep caterpillars in an aquarium or a 1-gallon jar. Fasten the top with a screen or cheesecloth. Secure the screen or cheesecloth with a rubber band. Provide the caterpillar sticks to pupate on.

Feed the caterpillar leaves from the plant that you found it on or provide the caterpillar with a selection of leaves to determine which it likes best. Let the caterpillar go if you cannot determine which is the right type of food. A caterpillar will starve before it will eat the wrong food. Feed the caterpillar fresh food once you have determined the type of food that it eats. Caterpillars will not eat dry, old food. Put a potted plant in the caterpillar cage to ensure that it always has food to eat.

Wash your hands before handling caterpillars, as they are susceptible to bacteria and infections. They are fragile, so handle them gently. Put a new host plant in the cage and allow the caterpillar to crawl onto it from the old host plant. Do not pull the caterpillar off the plant it is is on. It will cling tightly to whichever surface it is on, and you could harm the caterpillar if you try to pull it off.

Give butterfly caterpillars stems to pupate on. Put two inches of soil in the cage of a moth caterpillar for it to pupate. The pupa is a stage in the life cycle of a butterfly when it is surrounded by a cocoonlike encasement called a chrysalis. If you are unsure what type of caterpillar you have, provide it a choice of places to pupate.