Invasion of The Ants

What's with these creatures? Don't they know there's PLENTY of food/water/whatever they're seeking OUTSIDE my office window, conveniently open at the moment? Why do they have to take over the desk, the chili plants, the floor? What on earth do I have in here that they can't get outside??? They're random-wandering, "just looking", window-shopping. No set pattern, it's every ant for itself. And as much as I believe every creature has a right to it's own little bit of living, the temptation to squash one as it passes is pretty hard to resist...