What primarily drives the growth of insect larvae after they hatch from eggs?

The growth of insect larvae after they hatch from eggs is primarily driven by feeding. At this life stage, larvae, often referred to as caterpillars or maggots depending on the species, are in a critical phase known for their rapid development. Their primary task is to consume as much food as possible to gather the nutrients and energy necessary for growth.

By feeding extensively on their food sources, which can range from leaves to decaying organic matter, larvae undergo significant size increases as they store energy for their next life stages. This feeding behavior is essential for their transformation into larger, mature insects, as it prepares them for the more energy-intensive processes of metamorphosis that follow.

In the context of the other options: while reproduction is significant for adult insects, larvae primarily focus on growth through feeding. Resting does occur, but it is not a primary driver of growth; rather, it is a necessary part of their life cycle. Metamorphosis is a process that occurs later and is the transformation into adulthood, which relies on the growth achieved during the feeding stage. Thus, feeding is the correct focus for understanding larval growth.