My "predators" stick to bumble bees and spiders. Haven't killed one yet. They too eat grass and then run into the house to cough up hairballs and make deposits in the litter box. To be fair, all four were indoor cats in NYC and have no real hunting skills. One actually squawks and coos as she "sneaks up" on a bird or squirrel. They look at her as if she is daft and move on. Better than a bell.

I believe I would react to a broken bottle at my doorway as a threat and invasion of my space if not my home. weepiper has every reason to be angry. Hope this is a onetime event perpetrated by a drunken lout who didn't even know whose house it was.