I used to work in a nightclub and every Friday night, for months on end, when tidying up we would find hidden somewhere in the club a pint glass containing shit and piss. It was never hidden in the same place but we knew it was there somewhere and obviously couldn't be left so we had to hunt until it was found, like the world's most disgusting treasure hunt. We checked CCTV, increased glass collections, banned glasses from the toilets, and so on and the shit-glass still appeared every Friday night.
I briefly worked in a hotel in my early 20s when I needed some extra cash for Christmas and that was fucking grim. Used condoms left in the bed or on the floor or thrown and left where they landed. Shit in the bath. Shit on the bath towels. There was a long term resident, his company was putting him up in a suite while he was doing work in the area, and he kept pissing in the wardrobe. He was eventually asked to take his custom elsewhere. Sick in the lifts, sick under beds, sick sprayed up the inside of closed bedroom windows. Blood. Period blood on floors, on bath towels, used sanitary towels stuffed down the back of radiators or left floating in the loo. I always refused to clean up sick and blood. I'd be given a list of rooms to clean at the start of my shift, some would have notes added such as 'RS' which mean the guest had ordered room service the night before so you'd know that there might be trays or bottles or whatever to send back to the kitchens. One morning I walked into a room tagged on my list as 'RS' and found that the guest had indeed ordered room service. He'd ordered three dozen bottles of Coke, the single serving glass bottle ones, and when those bottles were empty he had refilled each and every one with piss. He had then placed them all over the room. They were on every surface, balanced on top of the TV, lined up along the headboard, balanced on the curtain rail. I radio'd for the head housekeeper and she came up to see, she looked at the room and then went to go into the bathroom presumably to see what damage he'd done in there, when she pushed the bathroom door open three piss bottles that had been balanced on top of the door fell off and shattered so then there was glass everywhere as well as piss. While cleaning it up we also found that he'd pissed in the kettle, pissed in both coffee cups, emptied out the little plastic UHT milk cartons and pissed in those, emptied the complimentary shampoo and shower gel and pissed in the empty bottles and, because he hadn't done enough already, he'd also pissed in the bit of steam iron where the water goes.
People are fucking animals.