A beetle in the bathtub

The spider beetle, Gibbium aequinoctiale.

About once a year, first thing in the morning, I find one of these in my bathtub.

It stands out against the white background. It’s dark red, about one eighth of an inch long, and has a bulbous body, tiny head, and long expressive antennae the same color as its three pairs of legs. It sits in the tub, unexplained. If I touch it, it curls up and plays dead.

It’s a beetle, although it doesn’t fit most people’s mental image of a beetle. There are more than 350,000 kinds of beetles, and they come in lots of shapes and colors. This one looks a little bit like a spider because of its round body, and the long antennae can be easily mistaken for another pair of legs, which would add up to eight -- the number of legs on a spider.

Spider beetles also get misidentified as bedbugs pretty often because of they are the same color. Everyone is always happy to find out they are wrong about that!  Bedbugs are flat, not globe shaped.

Scientists usually report that spider beetles eat “a variety of dead materials of animal and plant origin,” including flour, old wood, seeds, wool, feathers, leather, and fabrics. Spider beetle can be pests of stored food products, and actually will eat almost anything dry, including more appealing sounding things like breakfast cereal, figs, instant soup mix, rye bread, spices, and chocolate powder. 

Hmmm. None of these things are ever found in my bathtub…so why do I always only ever find spider beetles there?

They forage at night, and most of them scurry back to their day resting places before I rise. But about once a year, an errant beetle making its nightly rounds discovers the dark bathroom. They are attracted to moisture. Exploring. Climbing. Oh no! It falls into the tub! It can’t get out! Morning comes, and behold – there is a beetle in the bathtub.

There is more information about spider beetles in my book, A Field Guide to Urban Wildlife of North America, which will be published by Stackpole Books in spring 2011.