I put the caterpillars with some host plant in a plastic container with a lid, with air holes. Then put the container in an insulated box with a small frozen gel pack, separating it from the gel pack with a wad of newspaper. Shipped Priority Mail (3-day).Click to see full answer. Beside this, where do you get caterpillars?Look on the grass and on the leaves of nearby plants for caterpillars. You can also dig into the thatch in your lawn where caterpillars may be hiding or look in piles of decaying leaves, fruits or other vegetation. when should I order caterpillars? Yes, we ship caterpillars all year-round. You can order caterpillars during the winter if the temperature in your area is above 40°F for the next 7 days. Considering this, how are butterflies shipped? Shipping process Your butterflies are carefully placed into an envelope. This protects each butterfly and their wings assuring that they arrive in perfect shape for your event. The envelopes are then packed securely into a small box to prevent movement or damage to the butterflies during shipping.What time of year are caterpillars around?Large white caterpillars can be seen from June to September. Adults are active between April and October, when they lay bright yellow eggs on the underside of the leaves of plants that the caterpillars feed on.