Things You'll Need
- Coffee can with lid
- Window screen
- Glue
- Scissors
- Yogurt cup
- Leafy branches
- Spray bottle
Instructions
Cut a large hole in the lid of a coffee can, and glue a piece of aluminum window screen over the hole.
Pick up the caterpillar in the wild by breaking off the leaf or branch where it is resting. Some caterpillars have hairs or secretions that can irritate skin, so you don't want to touch them directly. If you find the caterpillar on the ground, use a stick to nudge it onto a leaf.
Pick some branches from the caterpillar's host plant.
Cut a hole in the top of a yogurt cup or other small container. Fill the container with water, and poke the branches from the host plant into the cup. The leaves won't wilt as quickly if they're kept in water.
Place the yogurt cup with the leafy branches inside the coffee can. You can put the branch with the caterpillar on it inside the can, or you can nudge the caterpillar onto the new branches with a stick.
Remove any wilted or stripped branches. Add more leafy branches as the caterpillar consumes the leaves. After awhile, the caterpillar will stop eating and will wander off the host plant. That means it's ready to spin a cocoon or create a chrysalis. The timing depends on the temperature, the species of caterpillar, and how old it was when you got it.
Provide a horizontal branch in the can so the caterpillar can attach itself.
Wait for the caterpillar to emerge as a moth or butterfly. The process may take months, but you can tell when it is coming because the cocoon or chrysalis will change color a few hours in advance. Make sure the enclosure has enough open space so the adult can stretch out its wings to dry.
Release the adult back into the wild so it can find a mate.