Is anything more frustrating than an ant infestation? At this time of year, lots of people encounter the little pests... Infestations aren't necessarily caused by messiness. The weather may be what drives them inside in the first place. Very rainy weather can cause them to go indoors seeking shelter, and drying up may draw them back out, eventually. However, once they're in, if there are crumbs or other food available to them, they could be tough to get rid of.
Even Buddhist monks in Kuala Lumpur have problems with them, trying to eradicate the pests without breaking their vow of nonviolence.
One of the more helpful sites we found is at Pest World, where solutions are given based on the type of ant you have in your home.
ATSF has an excellent post on Eco-Friendly Ways to Get Rid of Ants. We read that non-toxic methods are often not as effective as others, but we'd start here and step it up only if necessary.
Other tips include sealing up cracks and crevices where the ants could be entering, scrubbing around entry points with a detergent (to remove the trail pheromone) and spraying a residual insecticide around entry points.
For lots of good reader tips, also check out ATNY's Good Questions: How To Get Rid of Ants? Yuck! from a year ago.