Any young insect from the time that it hatches from the egg until it becomes a pupa, or chrysalis. During this time it usually molts several times, and may change its form or color each time. The larvæ of many insects are much like the adults in form and habits, but have no trace of wings, the rudimentary wings appearing only in the pupa stage. In other groups of insects the larvæ are totally unlike the parents in structure and habits, and are called , , , etc.

The early, immature form of any animal when more or less of a metamorphosis takes place, before the assumption of the mature shape.