Today we have had a guest in the bathroom sink. He keeps to himself and we try not to dislodge him with splashed water. Apparently he is nocturnal so overnight he'll probably move somewhere he can find more food.

I think he is a yellow sac spider. If you look closely you can see his eight eyes. I do not know enough spider anatomy to know what the two bulbous black shiny bodies are below his eye. But I think they may be his pedipalps, held a little like a boxer holding his gloves to his chest.