The Rat King Phenomenon
A rat king is a intertwined group of rats bound together at their tails by hair or sticky substances like sap or gum. Very few instances of rat kings have been observed in modern times but there are historical reports of rat kings which date back all the way to 1564. Most of the examples in this record are of black rats and some specimens are preserved in alcohol in several museums in Germany.
The first rat king discovery was from a farmer at Racphen, Netherlands, who found seven rats whose tails have callused from multiple days of struggling and entanglement.
There are many possible explanations for this strange natural phenomenon, theories range from the rats being tied together since birth to some deliberately knotting themselves to create a nest. Another possible explanation occurs in winter, where the natural secretion of the rats’ skin freezes and acts as a bonding agent as the rats sleep together in close proximity.
However, many century-old specimens could be hoaxes, with the knots of the rats’ tails being fabricated. Throughout history, rat kings have been associated with bad omens, particularly plagues — fabricated rat kings could have been used to invoke fear.