If you looked at the contents of a vacuum cleaner bag with a microscope, you'd probably find millions of tiny creatures called mites. These tiny critters feed on the dead skin of animals and humans, dust, and anything else you can think of. Mites are not insects. They are arachnids, related to spiders and scorpions. Most kinds are harmless to humans and play an important role in the environment.

Image credits: main image, courtesy of Mike R. Meyer/3 dot studio.