little mysteries

Came home yesterday to find two little puddles in odd places on the concrete floor. Didn't smell like anything, looked like and seemed to be water. No trails leading to anywhere they might have come from, not near the cats' water bowl, no discernible patches or leaks to have made them.

Ghost piddle? Condensation from the metal girders on the ceiling 14 feet above? (it has been mega humid) Spontaneous water?

It's like that time there was a dead finch (which definitely wasn't there when I left) in the loft when I came home, all the doors and windows shut.

Ideas?