The rat sniffs up to the narrow metal box, senses food and warmth, and strolls through the narrow entrance. But before its mouth can water, the gnawing nuisance trips an infrared light.
The rodent has tripped the Ratapult, a trap that flings the critters up to 50 feet into a cage or bucket.
For centuries rats have skittered their way over land and sea, spreading disease and gobbling crops.
Allen Gross, the Ratapult inventor, wants to send them flying.
"It's so fast you don't really see it, just a blur," said Ann Koenig, an Oakland businesswoman who helped Gross develop a manufacturing and marketing plan.
The device, not yet available in stores, will retail for $350 to $450.
Gross said he built his first trap two years ago and tested it in a friend's warehouse, where it launched 70 rats in two days.
The vaulting vermin lands in a bucket or cage, dazed but otherwise unharmed, where he can be turned over to authorities or released in the wild, he said.
"I didn't want the (rodents) squashed or turned into meatloaf," said Gross, 40.
Although the trap sends rodents flying with a startling snap, Gross and Koenig insist the Ratapult is humane. Mice and rats launched during a series of test flights were a little shaken up but otherwise unharmed, they said.
Animal rights activists are disturbed.
"It sounds medieval and it just sounds cruel," said Lynn Spivak, spokeswoman for the San Francisco Society for the Prevention of Cruelty to Animals. "It would certainly cause a certain amount of trauma to get flung though the air and flopped into a bucket."
But Gross said the catapult is a critical part of the trap. Unlike other rodent traps, the Ratapult resets itself, free of human scent and the smell of death.
It can be set to fling rodents anywhere from a foot to about 50 feet.