“What is this?” asks this reader in her submission regarding the brown, segmented, worm-like creature pictured below. “We found some small doughnut shaped eggs in our sandbox and we watched one of them hatch into an inch-long caterpillar! Here is a photo of the egg and one of the hatched larva!” Based on the excellent photo of the critter itself, we would say these are tomato pinworms, a type of moth caterpillar that, as their name suggests, eat tomatoes. They also eat potatoes and eggplants, as well as different types of weeds. With that said, tomato pinworm eggs do not look like the ones our reader found. The doughnut shape reminds us more of gall wasp eggs. However, gall wasp larvae do not look like the creature our reader found: they are white in color.