Nursery web spider (Pisaura mirabilis) carrying an egg sac under her ventral carapace with her palps. The female lays her eggs in early summer, storing them in the egg sac, which she then carries around beneath her body. In midsummer, when the young are about to emerge, she hangs the sac on low vegetation and weaves a 'nursery' tent of fine silk strands around it. The young emerge and remain in the tent, with their mother on guard, until their second moult, when they disperse.