Orb weaver spiders can be found all over the world. There are over 4,000 different species of them. They have two body segments, including a cephalothorax and an abdomen. They have eight legs, all of which are connected to the cephalothorax.
Orb weaver spiders have venomous glands that produce a toxin used to paralyze their prey. Their body length ranges from three millimeters to 30 millimeters. Orb weavers that are nocturnal have typically either a brown or black color, while the diurnal species are more brightly colored and usually black and orange or black and yellow. Female orb weaver spiders are generally larger than the males.
Orb weaver spiders are found in terrestrial, temperate and tropical habitats. They do not do well in low temperatures below freezing and have a lifespan of around one year. These spiders have poor vision and communicate through touch or vibrations in their webs. Their webs are constructed of neatly spun silk and are flat. Orb weaver spiders usually build a new web every day. Orb weavers that are brown or black build nests at night to avoid being seen by most birds, and those that are colored brightly tend to build their webs in the morning using their noticeable coloring to show they are venomous. Their main predators are wasps, birds and other spiders.The spiders come in a wide variety of shapes and sizes. The males, which are smaller than the females, do not usually build webs and spend most of their time searching for mates.
With eight eyes but poor eyesight, orb weavers depend on their webs to catch their prey. Vibrations in a spider's web alert her to the presence of prey caught in the sticky circular threads. When she feels the vibrations, she runs along the non-sticky radial strands to capture the insect, which she subdues with a bite. If she does not eat the insect immediately, she wraps it in silk for later consumption.
Orb weavers are beneficial to humans because of their role in controlling insect pests. They are not aggressive and usually flee when threatened. Their bites are not dangerous to people or pets.