Sea lice: who bites on the beach and in the water? (7 photos)
These small but terrifying monsters manage to simultaneously destroy salmon farms, bite swimmers for various reasons, and attack vacationers right on the shore. 
What are you?
In fact, the main monster here is the ignorance of people who blindly lump everything into one basket. Sea lice really are found in the oceans, and everywhere. They're an entire family of crustaceans, with 600 species, that survive by parasitizing fish. And while some are relatively harmless and simply feed on mucus, others burrow under the scales and suck the blood from fish, causing enormous damage to both wild populations and "domesticated" fish on farms. 
Help...
But no species of lice has been known to deliberately bite humans. Only occasionally, out of stupidity, do their larvae bite a person, but these are isolated bites that would leave no trace on a healthy person. And yet, if you search for "sea lice bites," you'll get a whole bunch of photos of bright red, inflamed rashes that itch disgustingly even through your computer screen. Something doesn't add up, don't you think? 
This is especially common in Thailand, for example.
What doesn't add up here is the poor translation by content creators and SMM specialists, whose main job is to fill the site with content, not be responsible for its quality. They often overlook the fact that in English-speaking circles, sea lice are used to refer not only to fish parasites, but also to small jellyfish and their larvae, which are abundant in the shallows of tropical and subtropical waters. These jellyfish are capable of causing pain to humans, albeit without causing significant harm. 
A typical microjellyfish, of which there are thousands. It's impossible to spot them with the naked eye, yet the warm ocean waters are chock-full of them.
They don't bite—they simply have nothing to bite with—but they have stinging cells that inject small doses of nerve venom under the skin. It sounds scary, but it's not as dangerous as it might seem. Yes, sometimes you can get caught in a large swarming of jellyfish larvae, especially during high and low tides. But the most a healthy person will get is a series of small, burning irritations that will subside within a few days. However, if you see an adult jellyfish, it can truly be dangerous, and it's time to swim to shore. Jellyfish larvae aren't interested in fish, at least until they grow up. 
Many adult jellyfish already contain a significant concentration of venom, and they easily paralyze small fish.
Some even classify sand fleas as sea lice. These are parasitic insects with a very nasty disposition. Their females burrow under the skin of mammals and grow there, feeding on human or animal blood. The flea torments its host for about a week, constantly growing in size and preventing the wound from healing. After which, it releases a couple hundred eggs and leaves the host, leaving a gaping wound open to infection. Horrible. But these parasites are rare, and they are usually absent from civilized beaches. On uninhabited beaches, it's best to wear slippers. 
A female sand flea, extracted from some poor soul's leg. 
Despite the sand flea's resemblance to a crayfish, it is actually a common insect.
So what conclusion can be drawn from all of the above? It's the same old story. The internet has become all mixed up, and sea lice, which are a nuisance to the fishing industry but generally harmless, have been turned into a "danger to tourists." In reality, a bite from a real sea louse is almost impossible, and that's a good thing.
