Alberta has maintained a rat-free status for over 70 years through active control measures, but the discovery of a dead rat in the town of Bowden has challenged this reputation. The province's rat-free status is attributed to geographic isolation, climate conditions, and a comprehensive control program established in 1950, though rising rat populations globally due to climate change pose ongoing threats.
A rat king is a collection of rats or mice whose tails become intertwined and bound together through entangling materials, sticky substances, or deliberate binding. The term originated in German as a metaphor for parasitic individuals before referring to the actual phenomenon, with the earliest documented report from 1564. Museum specimens and modern sightings, including a live example found in Estonia in 2021, confirm it is a rare natural occurrence.