With six inches of snow on the ground, I encountered two customer homes on Monday with live ants inside. For pest control professionals here in the northern half of the United States, winter time means slow time. We still have preventative services, mouse control jobs, German roach work, but rarely do we have ants inside in January.
What was so bizarre about these two homes? Nothing bizarre at all, actually--except that they were both concrete slab construction, which is the minority here in the midwest. They both had a heat source warming that concrete slab near the ant activity. And they both had food available readily available inside.
From the ants' perspective, life is good. We're living under this nice warm rock. It's not too wet--not too dry--and we have free food just on the other side of this little crack in the concrete.
One of the two ant infestation locations was a laundry room. The running dryer kept the slab warm and when loading dirty clothing into the washers, crumbs often fall to the floor leaving a smorgasbord of ant sized meals.
The other situation was sourced at the compressor at the back of a refrigerator, warming the floor near the sticky, syrupy remains of a hidden spilled soda.
Slab construction + heat + food = ants in January.