Fleas, mosquitos, bedbugs, scorpions, lice, and ants bite and run. Chiggers, scabies and other mites burrow and stay. Bumble bees, hornets, wasps and yellow jackets sting and sting again. Honey bees sting, leave their stinger in you, and go off to die. Spiders can repeatedly bite.
Black widows inject a neuro toxin that can cause severe muscle spasms.
Ticks hang on and suck your blood. When your blood attempts to clot, they inject you with an enzyme through their saliva that can contain Lyme or Rocky Mountain Spotted Fever bacteria. If possible, kill and keep any bug you don't recognize, especially ticks and spiders. Bring them if you come in. Check your wound for and remove any dirt, tiny tick, tick parts, bee stingers, etc.