bulge on the thorax, or are plumper, with long bristles jutting out from the sides. These bristles will collect debris and food remains – the empty integuments of aphids, most notably – that provide camouflage from birds. Eggs are deposited at night, singly or in small groups; one female produces some 100–200 eggs. Eggs are placed on plants, usually where aphids are present nearby in numbers. Each egg is hung on a slender stalk about 1 cm long, usually on the underside of a leaf. Immediately after hatching, the larvae moult, then crawls up the egg stalk to feed. They are voracious predators, attacking most insects of suitable size, especially soft-bodied ones (aphids, caterpillars and other insect larvae, insect eggs, and at high population densities also each other). The larvae may also occasionally bite humans, possibly out of either aggression or hunger. Therefore, the larvae are colloquially known as "aphid lions" (also spelled "aphidlions") or "aphid wolves", similar to the related antlions. Their senses are weakly developed, except that they are very sensitive to touch. Walking around in a haphazard fashion, the larvae sway their heads from one side to the other, and when they strike a potential prey object, the larva grasps it. Their maxillae are hollow, allowing a digestive secretion to be injected in the prey; the organs of an aphid can for example be dissolved by this in 90 seconds. Depending on environmental conditions, pupation which takes place in a cocoon takes about 1–3 weeks; species from temperate regions usually overwinter as a prepupa, though C. carnea overwinters as newly hatched adults. Use in biological pest control While depending on species and environmental conditions, some green lacewings will eat only about 150 prey items in their entire lives, in other cases 100 aphids will be eaten in a single week. Thus, in several countries, millions of such voracious Chrysopidae are reared for sale as biological control agents of insect and mite pests in agriculture and gardens. They are distributed as eggs, since as noted above they are highly aggressive and cannibalistic in confined quarters; the eggs hatch in the field. Their performance is variable; thus, there is interest in further research to improve the use of green lacewings as biological pest control. Species that have hitherto attracted wider study and are more or less readily available as captive-bred eggs to deposit out for hatching in pest-infested plant