By Barbara Walvoord
(First appeared in the Lathrop Lamp Post Jan. 12, 2017)
There are secret tunnels all over the world–in Egyptian tombs, medieval buildings, prisons, battlefields, and under walls meant to keep people in or out.
Tunneling seems part of our DNA: When our grandchildren found a huge snowbank left by snowplows near our townhome, they set about digging a tunnel into it.
Our grandchildren only got a few feet, but there are yards, perhaps miles, of secret tunnels all over Lathrop land. When the snow is deep, these tunnels, made by mice or shrews, are invisible to us. But as snow partially melts, the tunnels become visible, and we can see how extensive is the under-snow life on our land.
For mice and shrews, a tunnel under the snow is warmer than the surface. It keeps off the wind. And it provides some protection against predators. The little creatures tunnel out discrete places to sleep, move from one source of seeds to another, store food, and poop.
But I said “some protection” against predators. Owls and hawks listen for the movements of mice and shrews in their tunnels, and swoop down through the snow to grab one. It’s like a horror movie in which a huge bird-like dinosaur suddenly crashes from the sky through the roof of your house and snatches you away.
So outdoor tunnels are useful, but for a mouse in winter, the best tunnel is the one that leads into your house. However, the ones that didn’t come live with you this fall are still out there, in their thousands, making their tunnels under the snow, and providing dinner for our owls, hawks, foxes, coyotes, and bobcats. The mice in your house are probably breeding like crazy, but the ones in the snow tunnels won’t breed until spring–it’s too cold for the babies, who are born without fur, blind and helpless. Once they’re born, though, they’re ready to go in 21 days, along with their 4 – 11 siblings, and in 3 or 4 weeks, Mom will have another litter, on and on, throughout her lifespan of about a year. No wonder we have all those tunnels at Lathrop.