Most of us our familiar with the phrase; “No need to reinvent the mouse trap.” When in fact, mouse traps have been reinvented or improved several times. And it all started with springs.
The first lethal trap was a set of spring-loaded, cast-iron jaws named “Royal No. 1”. The trap [was patented on 4 November 1879 by James M. Keep of New York, US patent 221,320. This is not the first mousetrap of this type, but the patent is for this simplified, easy to manufacture, design, which it relied on the force of a wound spring rather than gravity to capture a mouse.
The jaws 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 mouse.
Lightweight traps of this style are now constructed from plastic. These traps do not have a powerful snap like other types. They are safer for the fingers of the person setting them than other lethal traps and can be set with the press on a tab by a single finger or even by foot.
Another spring-loaded mousetrap was first patented by William C. Hooker of Abington, IL. who received US patent 528671 for his design in 1894. A British inventor, James Atkinson a similar trap called the “Little Nipper” in 1898, including variations that had a weight-activated treadle as the trip. It trapped mouse in spring-loaded bar trap.
In 1899, Atkinson patented a modification of his earlier design that transformed it from a trap that goes off by a step on the treadle into one that goes off by a pull on the bait. The similarity of the latter design with Hooker’s of 1894 may have contributed to a common mistake of giving priority to Atkinson.
It is a simple device with a heavily spring-loaded bar and a trip to release it. Cheese may be placed on the trip as bait but other food such as oats, chocolate, bread, meat, butter and peanut butter are more commonly used. The spring-loaded bar swings down rapidly and with great force when anything, usually a mouse, touches the trip. The design is such that the mouse’s neck or spinal cord can be broken, or its ribs or skull crushed, by the force of the bar. The trap can be held over a bin and the dead mouse released into it by pulling the bar. In the case of rats which are much larger than mice, a much larger version of the same type of trap is used to kill them. Some spring mousetraps have a plastic extended trip. The larger trip has two notable differences over the smaller traditional type: increased leverage, which requires less force from the rodent to trip it; and the larger surface area of the trip increases the probability that even the most cunning of rodents will set off the trap. The exact latching mechanism holding the trip varies a lot and some need to be set right at the edge in order to be sensitive enough to catch cautious mice.
In 1899, John Mast of Lititz, Pennsylvania, filed a U.S. patent for a modification of Hooker’s design that can be “readily set or adjusted with absolute safety to the person attending thereto, avoiding the liability of having his fingers caught or injured by the striker when it is prematurely or accidentally freed or released.” He obtained the patent on 17 November 1903. After William Hooker had sold his interest in the Animal Trap Company of Abingdon, Illinois, and founded the new Abingdon Trap Company in 1899, the Animal Trap Company moved to Lititz, Pennsylvania, and fused with the J.M. Mast Manufacturing Company in 1905. The new and bigger company in Lititz, however, retained the name Animal Trap Company. Compounding these different but related patents and companies may have contributed to the widespread mis-attribution of priority to Mast rather than Hooker.
Since the spring-loaded mouse traps, there have been other types of traps invented including; electric traps, live-capture mouse traps, glue traps, barrel traps and disposable traps.