Spider Pictures, Pictures of Arachnids, Facts, and Information

Pictures of spiders and other arachnids, including scorpions, with detailed information.

The arachnid family includes over 100,000 known species including spiders, scorpions, harvestmen, ticks, solifugae, and mites. Most of those species are terrestrial, but a few live in marine environments. Nearly all arachnids have eight legs, whereas insects only have six. The difference in the number legs is the most common way that people decipher insects from arachnids, but you can also distinguish them by remembering that arachnids never have antennas or wings.

Arachnids are mostly carnivorous and feed on pre-digested bodies of small animals and insects.  Some arachnids use venom to kill their prey. Unlike other animals, which digest their food with acids once they are in their stomach, arachnids spit their digestive juices on their prey to break them down before they ingest them. Other arachnids, such as ticks and mites, are parasitic and feed off of the blood of other animals.

Some arachnids, such as spiders, lay eggs after mating. Conversely, scorpions and a few other species give birth to live young.

The most famous arachnids, spiders, make an amazing silk that they can use to make webs to catch their prey, spin their prey to restrain it, climb, make burrows, and hold sperm for short amounts of time. Some species of spider can even use threads of their silk to help them glide through the air!

Opiliones, also known as daddy longlegs, do not make silk or have venom. They gained their nickname from their very long legs. Some species have a leg span of 6 inches! They are completely harmless to humans and feed on plants, scavenge some decaying animals, and fecal matter.