This projects show you how to prepare a home for caterpillars on plants where you see half-eaten leaves – they may be hiding on the undersides. Take some of these leaves with the caterpillars you find. Use a field guide to identify the species you have found, and which plants they prefer. Try not to touch caterpillars directly with your fingers, since some species may sting. Pick them up with a paintbrush, or encourage them to climb onto a leaf. Carry them in a jar. At home, keep the caterpillars out of direct sunlight, in a moist, cool place. Try not to disturb them. Clean the box regularly, and replace old leaves with fresh ones.