The loon is a large diving bird that lives on lakes and coastal waters across the northern parts of North America, Europe, and Asia. Loons are excellent swimmers and divers, using their powerful webbed feet to chase fish underwater. They can dive as deep as 200 feet and stay submerged for several minutes while hunting.

What makes loons especially memorable is their haunting, echoing call that carries across northern lakes at dawn and dusk. Their cry sounds like wild, trembling laughter mixed with a sorrowful wail. This eerie sound has made the loon a symbol of wilderness and remote northern forests. If you've ever watched a movie set at a summer camp or on a remote lake, the soundtrack probably included a loon's call to create that wilderness atmosphere.

Loons have striking black and white plumage during breeding season, with a black head and a distinctive checkerboard pattern on their backs. They're awkward on land because their legs are positioned far back on their bodies (perfect for swimming, terrible for walking), so they rarely leave the water except to nest.

The phrase crazy as a loon or simply calling someone a loon means they're acting wild or irrational. This expression likely comes from the bird's strange, laughing call and its splashing takeoffs from water.