It’s difficult to describe (or even recall) the sequence of events that occurs when your cat drops a live Deer mouse into your armpit while you’re sleeping. Chaos descends, your lizard brain switches on, and you’re instantly transformed into a roiling mass of flailing, kinetic energy. This is otherwise known as “going berserk”.
All for a mouse.
If you live on the East coast—especially in wooded suburbs—Deer mice (Peromyscus maniculatus) and White-Footed mice (Peromyscus leucopus) are critters you might already be familiar with. As far as mice go, they just might be THE cutest of all the mouse species. Their gigantic eyes and enormous ears make them almost cartoonishly adorable.
These two very similar (and closely-related) native mouse species inhabit our woodlands, and distinguishing the Deer mouse from the White-footed mouse can be a bit tricky. Typically the Deer mouse has a bi-color tail with a sharp definition from the darker color on the top and the lighter color on the bottom; meanwhile, the White Footed mouse also has a bi-tone tail--but but separation between the colors is much more indistinct. While both species inhabit my property, it seems White-Footed mice over-represent those which frequent my basement. White-footed mice also make an interesting noise when alarmed, which is sort of a buzzing sound which they produce by drumming their front feet on a surface—and it’s a noise I’ve become quite familiar with!
While sources online will say Deer/White-Footed mice in your house is unusual and homeowners are more likely to encounter the House mouse (Mus musculus) as an unwanted guest, I can say that in all the decades I’ve been in Bridgewater, I've never once had a House mouse---but have dealt with hundreds of Deer & White-Footed mice in my time here. If you have mice in your house that have a brownish grey or cinnamon-colored upper coat with a bright white belly and feet, you’ve got Deer/White-footed mice. House mice are also known for their musky odor which Deer/White-Footed mice lack.
White-footed mice are a native non-game species which can be quite beneficial since they have a near-insatiable appetite for Spongy-moth caterpillars (Lymantria dispar)---and if you never heard of a ‘Spongy moth’, it’s probably because you know them by their former name, “Gypsy moth”. So, while having an infestation of mice in your house is never a good thing, live trap & release of these native species is preferred since they are important parts of our forest ecosystem and can help keep our trees healthy. White-Footed mice are in fact very arboreal and often nest in trees & tree hollows and are known to make use of old bird nests which they convert into their own globe-shaped nest. Interesting side note: Deer mice are an animal model used in the field of OCD (obsessive-compulsive disorder) research as they’ve been proven to have repetitive, compulsive behaviors (large nest building, running in patterns, and vertical jumping) that meet the classification criteria of human OCD!
Deer/White-footed mice are also a favorite prey of foxes, owls, and other raptors (e.g. hawks and falcons), so, if you're looking to control them in your home, poisons should not be considered to control them. Also, please do not use glue traps as they are profoundly & unnecessarily cruel.
The good news is that I’ve found these types of mice easy to trap using humane traps like these -- and I simply release them in the rear of my property (or into my shed if caught in winter). White-footed mice have a range of about 500 feet, and considering they have a complex social structure, releasing them further away very likely causes their death---since they have neither a familial nest nor cache of food for survival (and they are known to cache substantial quantities of seeds, cherry pits, and acorns). And even though they stow away large amounts, winter starvation is the second highest cause of mortality after predation.
The best means of controlling them is exclusion—and they most often gain access via gaps around water/gas pipes—so fill those voids with expanding foam mixed with copper mesh or steel wool. If you have a house that’s more than 40 years old, you may have to just live with their occasional intrusion, as finding every space they can enter is nearly impossible.
While having indoor cats certainly can help reduce the numbers that make it inside, it’s quite typical that my cats often gift me with a live but permanently injured (i.e. non-releasable) mouse that ends up being a pet (which is legal to do with this species in NJ). We currently care for two such White-footed mice: 5yo Wheels and 3yo Stubs. One mouse we had lived to be 7yo—which is darn near the max lifespan of 8 years for a White-Footed mouse! So, if anyone ever wants tips on caring for a Deer/White-footed mouse, let me know—I’ve pretty much got it down to a science and apparently have unlocked the secrets to a long, happy mouse life.
Thankfully, many of our “gifted” mice are rehabbed and released—but we did have one which apparently liked his former arrangement so much that he returned every night to the basement to run on his old mouse wheel which was stored on a shelf (hmmm---perhaps he was one of those OCD mice?).
So the next time you have to give an eviction notice to a Deer/White-footed mouse, please consider opting for a humane trap & release…Bridgewater’s trees will thank you for it. Just keep your fingers crossed that one of them doesn't end up in your shirt!