A mousetrap is a type of animal trap designed primarily to catch mice; however, it may also, accidentally or not, trap other small animals. Mousetraps are usually set somewhere indoors where there is a suspected infestation of rodents.
The trap that is credited as the first patented lethal mousetrap was a set of spring-loaded, cast-iron jaws dubbed "Royal No. 1". It was patented on November 4, 1879, by James M. Keep of New York. From the patent description, it is clear that this is not the first mousetrap of this type, but the patent is for this simplified, easy-to-manufacture, design. It is the industrial age development of the deadfall trap, but relying on the force of a wound spring rather than gravity.
The jaws of this type are operated by a coiled spring and the triggering mechanism is between the jaws, where the bait is held. The trip snaps the jaws shut, killing the rodent.
James Henry Atkinson
The classic spring-loaded mousetrap was first patented by William C. Hooker of Abingdon, Illinois, who received a patent for his design in 1894. A British inventor, James Henry Atkinson, patented a similar trap called the "Little Nipper" in 1898, including variations that had a weight-activated treadle as the trip
The Little Nipper is the classic snapping mousetrap that we are all familiar with that has the small flat wooden base, the spring trap, and the wire fastenings. Cheese may be placed on the trip as bait, but other foods such as oats, chocolate, bread, meat, butter, and peanut butter are more commonly used.
The Little Nipper slams shut in 38,000th of a second and that record has never been beaten. This is the design that has prevailed until today. This mousetrap has captured a 60 percent share of the British mousetrap market alone, and an estimated equal share of the international market.
James Atkinson sold his mousetrap patent in 1913 for 1,000 pounds to Procter, the company that has been manufacturing the "Little Nipper" ever since, and has even built a 150-exhibit mousetrap museum in their factory headquarters.
American John Mast of Lititz, Pennsylvania, received a patent on his similar snap-trap mousetrap in 1899.
Austin Kness had an idea for a better mousetrap back in the 1920s. The Kness Ketch-All Multiple Catch mousetrap doesn't use bait. It catches mice alive and can catch several before it needs to be reset.