First, it may be food as ants are hungry, tiny creatures, scavenging for food like there’s no tomorrow. As soon as they find a source of nutrition, like countertops and pantries, they are likely to stay there. For a while.
Another reason may be moisture, as some species of ants thrive in damp wood, near cabinets, leaky pipes, and sinks.
Yet another thing you should consider is whether there are any cracks and crevices in your windows and doors. These tiny cracks can look like no big deal to you, but for ants, it’s basically a “Please, make yourselves at home” kind of invitation.