At night, they unwrap cheese and take dairy out of wealthier folks' iceboxes to have them develop rinds/spoil overnight. Also, they deliberately moisten bread with dew at night to make it go moldy, and put bits of rotten fruit next to meat in order to make them go maggoty in record time. Weird how everything keeps going rotten so fast, but not necessarily 'animal sabotage'.

Chickens escape their coops and hide their eggs in rather cleverer places than they should, so folks end up scratching their heads and wondering why they aren't laying. Cats and dogs promise to leave bunnies that wander into the garden alone. Owls start haunting people's houses for the express purpose of freaking them out.