A is for Arachnids.

The most common arachnid is the spider. Spiders can be distinguished from other Arachnids because the body is seperated into two parts, the combined head and thorax is separated from the abdomen by a narrow waist, in other Arachnids the whole body appears to be much more of a single unit.
Colorado is full of many different types of spiders, but my favorite is the Daddy Long Leg. These are the most commonly found spider in the home.
They do not sting or have venom. Daddy long legs feed on plants and sometimes decaying materials in forests.