You’ll never know until it’s too late.
Fun story time: a spider once laid eggs under the water reservoir of my espresso maker. I guess It was warm and dark there. I only found out when I noticed tons of little spider webs going from the espresso maker to the kitchen cabinets… with the hatched babies crawling on them. Much screaming occurred that day.
I cleaned the water reservoir itself regularly, but not under it. It was a spot you’d maybe clean once in a while.