What you caught was a woodland jumping mouse (Napaeozapus insignis), says wildlife biologist Mark Engstrom of the Royal Ontario Museum in Toronto, who identified it easily from the photo you sent. And they do jump, using those long, strong hind legs and feet to propel themselves much like a kangaroo does, instead of scuttling as most mice do.

You haven't killed a rare specimen, you'll be glad to know. However, like you and your neighbours, none of us at Cottage Life had ever seen one outside the picture in our field guide. We asked Ron Brooks, a University of Guelph zoologist who monitors small-mammal populations in Algonquin Provincial Park, why - though common throughout cottage country - they're not spotted more often.

They're nocturnal, explains Brooks, and are most often seen in car headlights, hopping "like superfrogs" on roadways at night. They're also hibernators and are inactive for several months of the year, unlike deer mice, which are active year-round. And though Brooks isn't sure why, it seems they rarely venture inside buildings. "I've never seen one in the cabins at Algonquin," he says, "even though they're abundant here. It could be because they forage more on live vegetation, or on seeds that aren't usually found in buildings."

So checking out your garden shed, and getting rid of any plant material or stray weed and flower seeds that may be clinging to tools and implements, might help you avoid trapping any more of them.