Chances are, you have probably never heard of a rat king, and are having disturbing visions of some sort of an alpha rat (or else a cartoon character) in your mind’s eye at the suggestion. In spite of the name, however, rat kings have nothing to do with rodent royalty. Instead, they are a little-known phenomenon that has reportedly occurred mainly with black rats over the past several centuries.

It is not even known for sure if the phenomenon is real, although judging from the museum displays of supposed rat kings, they are either real or very well faked. Because they cannot be 100 percent proven as fact, they continue to be categorized under the cryptozoological heading.

Now, what is a rat king exactly, you ask? It’s when a large group of rats somehow manage to get their tails fused together- either from excrement and filth, or from them becoming knotted together so tightly they cannot pull apart. It’s said that the animals grow together and their tails are often broken and badly calloused, which indicates that they have been in such a state for a long period of time. There is no particular number of rats in a rat king; one specimen has up to 32 rats, while another had only seven.

Rat kings have been reported since as far back as the middle ages, and for whatever reason seem mostly confined to Germany. They have been greatly feared and reviled as a very bad omen, most likely because of the diseases they carried. If one rat could mean the Plague, certainly a hideously connected group of them must mean something even far worse was in store for the populace!

It isn’t understood why, if real, it would primarily only affect black rats and not other species. What science has come to understand about the possibility of rat kings is how they are formed. It is believed that it happens on very rare occasions when a large population of rats cluster together inside their nest or other tight space, perhaps with their heads facing out to be on the lookout for danger. Other rats bring in food, so the animals have no need to leave, and eventually their tails become hopelessly entwined.

Since there are no reported sightings in modern times of any living rat kings, all one has to go on are a few mummified remains and the written word. It is unlikely that the existing examples are fakes, because X-rays seem to show that the animals’ tails were in fact growing together while they were alive.

Rat kings are one of those weird things in the natural kingdom, that if in fact real, have people scratching their heads and wondering how anything like that can exist.