Jeff Layman wrote:
Something has eaten through the stem of several of my tomato seedlings,
and it's almost certainly a snail. The the smooth crescent shape of the
"cut" always suggest to me something which does not have teeth, but
rasps the material away. With your damage, was there anything left on
the root side of the shoots? (in other words, was the offending beastie
after the seed/pea the seedling grew from?)

I was in a bit of a hurry, and definitely in a huff, so I didn't stop to
examine fair - I did try shoving a few of the stems back in in the vain
hope they may re-root, but ... Yes, I think there were kind of 'dug up'
bits, so I'm assuming it was a mouse after the pea. Probably came through
the vent, which is low and open to keep the place ventilated, but not as
windy as leaving the window open makes it. Ho hum.