The tiny corpse stayed in our freezer (swathed in multiple layers of plastic) until May, a cryogenic interlude intended to kill some subset of whatever microbia might be on board. Then I took it out, thinking to dissect the flesh off, but mouse bodies have a much higher moisture content than birds -- it was frozen solid, much too hard to use a knife on.
I whipped up a burial cage out of window screening and wire, and dug a shallow grave under the dogwood tree in my tiny front yard. (Very shallow...
Twice in two months, weather or squirrel activity unearthed the tiny cage and I covered it up again with loose dirt.)
By early July, nothing remained of the remains except bones, bits of fur, and the cartilaginous tail, along with a fair amount of dirt and empty insect casings inside the mesh envelope. I sifted and rinsed the debris, soaked the bones overnight in soapy water (using liquid dish soap), rinsed them again, and then soaked them in (3%) hydrogen peroxide for three hours or so.
|After soap, before peroxide. (Guitar pick for scale.)
The skeleton is missing some ribs and toes, one patella, and probably some other bits. But it's mostly there. Next step, deciding what to make...
I would definitely use the burial-cage method again, preferably with a volunteer a little bit larger than a mouse (those tiny bones were a struggle to rinse! Each rib was the size of an eyelash). I would use an actual trowel and bury it a few inches deeper to reduce disruptions. Our neighborhood squirrels are industrious.