Arachnid Facts

TarantulaPhoto by Ken Krahuec

Arachnid Facts

SpiderWhat does an arachnid look like?
  • An arachnid is part of the invertebrate family. This means they have no backbones (or bones at all). Instead, spiders have a hard outer shell called an exoskeleton.
  • Arachnids have two central body sections; the head and the abdomen. They have eight legs, which are attached to their head. All spiders have fangs that they use to inject venom into their prey.
  • Spiders, tarantulas, scorpions, ticks, and mites are all considered arachnids.
How big are they?
  • There over 600 species of spiders known to occur in Utah, ranging in size. The largest arachnid in Utah is the desert blonde tarantula, with a leg span of six inches.
Where do they live?
  • Arachnids are found throughout Utah.
What do they eat?
  • Almost all arachnids are carnivores eating insects and other small animals. Most arachnids cannot eat solid food, which is why most inject their prey with something (venom or digestive juices) to dissolve the protein so they can suck out the juice.
What eats them?
  • Because of their size, arachnids have many predators. Birds, toads and lizards will eat them, along with insects and larger arachnids.

Did you know?

TarantulaAll spiders are venomous, but most cannot hurt people. There are only a few spider species of concern in Utah, including the black widow. Most spider bites cause a slight irritation and swelling, similar to a mosquito bite or bee sting.

Spiders are a natural pest control, keeping populations of insects such as mosquitoes under control.

Threats to arachnids:
  • Pesticides can kill arachnids.