Halfway between my ankles and my knees.
However, if I am trekking in the wilds and have to go in the bush, I take them off when squatting, following a dodgey incident in Peru where i failed to consider the consequences of peeing at the same time as taking a crap
I take them right off, turn them round and put them back on. One can make poopies through flies. Ironic because the occasional smear does attract them.