Tilly had an exciting night. As usual, she got me up so she could go out and pee some time around midnight, only to find a skunk in the garden. She shouted at it, and it sprayed at her, but luckily she wasn't close enough that it hit her. Still, the garden smelled of skunk all night and into the morning.
Something's been digging under the back fence and in the lawn, so maybe that's solved that mystery.