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.

Order: Acari
Size: most mites cannot be seen with the human eye; they are microscopic
Habitat: found worldwide in gardens, dust, soil, leaf litter, and on living organisms
Diet: blood and skin of living and dead animals, plants, fungi, and other tiny insects
Characteristics: have mouthparts that can crush and pierce; are brown to red in color

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