There are ant species that 'farm' caterpillars. If you ever incorporate the ability to climb up twigs and branches, keep these gals in mind: https://australianmuseum.net.au/lycaenid-butterflies-and-ants
You could have a level where the objective is to keep them safe long enough to pupate into butterflies, so that next year you will have new caterpillar eggs laid.
You could have a level where the objective is to keep them safe long enough to pupate into butterflies, so that next year you will have new caterpillar eggs laid.