I was once a waitress. Can you believe it? LOL.
Anywho, at a national chain place that served "chicago style pizza", we had these giant iced tea bins. Once on the counter, they were very, very tall and you just pushed a button on the side to make fresh tea. At night, the bin is turned upside down after being cleaned, to prevent anything from crawling in.
It was my job to clean it one night, so I took the bin to the dish station, dumped it, and heard a loud, "THWACK!" I looked to see what it was, thinking maybe the filter fell into it....uhh, no. It was a dead, drowned rat. Apparently someone didn't turn it over, and it crawled in there during the night...then someone made iced tea, and it drowned.
Yes, the tea was served all day. Anytime I had a patron that wanted iced tea after that, I'd say the machine was broken.