any of about 3,000 species of spiders (order Araneida) known for their ability to jump and pounce upon their prey. They range in size from 3 to 17 mm (0.12 to 0.67 inch), although most are small to medium-sized. They are very common in the tropics, but many also live in northern and even Arctic regions. The hairy body is often brightly coloured or strikingly patterned. Jumping spiders have keen vision for spiders and are active during the day in sunny areas. At night they hide in closely woven nests under bark, stones, or leaves. Several members of the same species often build nests close together.