There's a mouse in the kitchen and it's eating better than I am

It got into the cereal again. I found the hole it chewed in the box. — Ground-floor renter, 1971

The U.S. Patent Office has granted more than 4,400 mousetrap patents, more than for any other invention. Plenty of inventors thought they'd improved on the old one. The trap people still buy is the flat wooden snap trap from the 1890s: bait on a small tab, and a spring-loaded bar that snaps shut when the mouse nibbles. Who invented it is a fight. One account credits William Hooker in 1894. Another says John Mast made it in 1899. The CDC still recommends the plain snap trap. Nobody has built a better one.

Noted: the CDC and the University of California's pest program both name peanut butter as the bait, and the CDC says a small dab on the pan is plenty.

The full file

Ralph Waldo Emerson gets the credit for the line about building a better mousetrap, and he probably never said it. His own 1855 journal entry doesn't have it. An admirer, Sarah Yule, wrote in a book in 1889, seven years after he died, that she'd heard him say a catchier version with the mousetrap in it.

The inventors mostly didn't do well. An American Heritage writer reported in 1996 that fewer than two dozen of the patented traps ever earned their makers a cent, and that 95 percent of the patents went to amateurs.

Where you put the trap matters as much as which one. The CDC says behind the stove and refrigerator and in the back of cabinets. The University of California's pest program says along walls and in dark corners, where a mouse runs over the trigger. Hooker's own patent describes a trap built "not to excite the suspicion of an animal."

Mice have lived in people's houses for about 15,000 years, since hunter-gatherers in the Middle East began to settle down. The trap is the newcomer.