An elementary school in Colorado went into lockdown Tuesday after loud noises—believed to come from gunfire—were reported, but further investigation revealed a squirrel as the culprit.

An elementary school in Boulder, Colorado, was put on secure status on Tuesday after a squirrel tripped an electrical wire and the sound was thought to be gunshots, according to officials.

The other day, when I was visiting my daughter in west-central Wisconsin and saw a ton of eastern gray squirrels that were jet-black, I thought this is something most people don’t know exists. The ...