A rat king is a cluster of rats whose tails knot into one living tangle. The largest, 32 rats, turned up in a German chimney in 1828 — and a live one in Estonia in 2021 finally proved the phenomenon is real.
The full history of the phenomenon: rats found with tails fused by blood, filth, ice or knots, recorded in Europe since the 1500s.
National Geographic weighs the hoax claims against the evidence and asks how living rats could possibly end up this tangled.
The record-holder, found in a chimney in Buchheim, Germany, and still preserved in a museum in Altenburg nearly two centuries later.
Live Science on a farmer in Russia who found five live rats knotted together in a flooded field — caught on video.
A live rat king found in Estonia in 2021 — only the second recorded this century — is treated as proof the phenomenon is natural but vanishingly rare.
A tour through the preserved specimens and the centuries of dread, omens and theories that surround them.
A visual explainer on how a rat king forms and why the knot only tightens the harder the animals struggle.
News footage of the rare multi-rodent rat king, the kind of find scientists see maybe once in a generation.