deer mice

[Monty]

I usually have a "few" deer mice in some of the boxes on my trail, but this year, they are pretty much infested. Every Friday when I check the trail, I have to, again, evict the mice and their nests.

The boxes that the tree swallows have claimed are now the only boxes that the mice are still trying to use. And I'm finding that the swallows, with no other option, are beginning to round out the center of the mice nests and put pieces of grass in as part of their own nest building.

My concern is: since mice will occasionally eat birds' eggs/young, if I have to allow them to co-exist with the swallows, will they prey on the birds' eggs/young? They'd be foolish not, as they would be an easy meal. I don't want to kill the mice, but don't want to lose this year's young swallows, not even hatched.

I've not had this problem before, and am not sure what my options are.

Monty