Life finds a way to survive virtually everywhere on our planet – including on itself. Almost every bird and mammal on the planet has its own unique species of louse: reptiles are home to scale-chewing mites, tiny crustaceans cling to the fins of fish, and even many bugs can have bugs of their own. Some of these bodily inhabitants are what biologists call “commensal,” meaning that they live on another animal but cause no harm nor benefit either way; the host never really even notices them. Others are of course “parasitic,” meaning they they cause some irritation or damage to the host as they feed on tissues or body fluids. Still other body bugs are “mutualistic,” meaning that both the body and bug are of some help to one another. Whether good, bad or just along for the ride, you can always expect these little critters to be weird.
10. Elephant Lice
Haematomyzus elephantis is a true louse, a parasite like the head lice that attack us humans, but can be found only on the bodies of elephants. Unusual among most lice, the jaws of these insects are on the end of long, thin snouts – almost like the trunks of their hosts. It’s far from coincidence, as the long snoot is used to penetrate an elephant’s thick, wrinkled hide.
9. Llama Lice
If it’s interesting that an elephant louse would have a long nose, certain lice that attack llamas and alpacas even happen to have long, thick necks. In this case, the neck allows them to reach through their host’s very thick and tangled hair to bite at the skin and suck blood.
8. Fish Lice
Insects are virtually absent from the sea, but fish aren’t safe from lice of their own. Argulus or “fish lice” are crustaceans, like crabs or lobsters, but adapted to a fully parasitic lifestyle. Their flat, saucer-shaped bodies act as powerful suction cups, clinging to their host’s slick, slimy scales even against a raging current. Just like the parasites of us air-breathers, these “fish lice” can transmit viral infections as they spread from one host to another.
7. Lobster Louse-Worms
Though shaped very much like lice, the Histriobdellidae are actually tiny annelids (like leeches or earthworms) who live a louse-like existence on the outer shells of crayfish, isopods and other crustaceans. While our lice have specially hooked claws for gripping hair, these louse worms have suckers for clinging to a smooth exoskeleton, and a powerful set of drilling jaws for getting at that tasty sea-bug blood.
6. Cockroach Mites
While lice are a kind of six-legged insect, mites are a kind of eight-legged arachnid, and can be found living on an even wider variety of other animals. Mammals, birds, reptiles, fish, and even fellow invertebrates can all harbor parasitic, mutualistic or commensal mites. For our example, I’ve chosen Gromphadorholaelaps schaeferi. This mite is found living exclusively on the bodies of giant Madagascan hissing cockroaches – a popular exotic pet and reptile feeder – where they devour microscopic fungi growing on the host exoskeleton. Without these mites, the roaches can even develop fungi that irritate human asthma, though it isn’t known if the roaches themselves benefit much from the arrangement. (Image of mites not available, video of Madagascar Hissing Cockroach – mites not visible.)
5. Bee Lice
No bigger than the head of a pin, insects of the “Braula” genus live clinging to the fuzzy body of a honeybee and feed on nectar straight from the host’s mouth, even tickling the bee’s face until it regurgitates. Interestingly, these “lice” are actually flies, like the common housefly, but completely devoid of wings. Why bother with them, when you live on another winged insect? Think of it like a tiny kiwi living on an eagle…and drinking its puke.
4. Naked Bat Earwigs
You’ve probably never heard of the Malaysian hairless bulldog bat, one of the world’s rarest bat species. Even more unusual, this oddball mammal is home to an equally oddball bug: a tiny, louse-sized earwig living in the folds of the bat’s naked, wrinkly body- where it is thought to feed on collected skin oils or other secretions. We aren’t really sure, because we barely know much about these bizarre bats themselves.
3. Beaver Beetles
Though they look like a cross between a flea and a louse, Platypsyllus are actually just highly unusual beetles (as are fireflies, ladybugs and weevils). They are found living solely in the nests and fur of beavers, but cause no harm at all. Feeding on dirt, dead skin flakes and even other bugs, these insects are generally considered commensal or may even be beneficial.
2. Snail Flies
If you thought the bee lice were weird, Wandolleckia is another genus of flightless fly, though in this case it’s only the female that lacks wings. They spend their entire lives swimming in – and eating – the slimy coating of the giant land snail, Achatina achatina, while the winged males fly from snail to snail mating with the lovely mucus-dwelling ladies.
1. Whale Lice
Reaching up to a full inch in length, these crustaceans might be the largest body bugs on Earth, which is hardly surprising considering that they live exclusively on whales, where they feed harmlessly off algae and flaking skin. Once overlooked by biologists, we now know that their genetics closely parallel the genetics of their hosts, differing between whale lineages and even between individuals as a part of every animal’s unique identity. This is particularly true for the three species of “Right” Whale, whose characteristic white “lumps” are actually thousands of lice clinging to special patches of rough skin. These patches serve no other known purpose, but the patterns of white lice make every whale immediately recognizable to observers and perhaps even to their own kind. Hey, at least it’s prettier than your driver’s license photo.