If you look closely at this cuckoo wasp you will see groups of small pale mites. Mites, relatives of ticks, are very common, though because of their small size are seldom seen. Mites are found almost everywhere, including in decomposing organic matter, in soil, on plants, and in water habitats. They play many vital ecological roles as predators and decomposers, while others are plant pests.
Other species, such as these ones, are found on the bodies of animal hosts, sometimes feeding on them, other times just hitching a ride. Some mite species live inside other animals, occasionally living in nasal passages and other orifices of vertebrates. Chances are, you have Demodex mites living on your eyelashes or other hair follicles.