Gap under baseboard, ants & dirt coming in

[Bienes Raices]

I've got the "anticide" or whatever it's called to put around the perimeter of the house, but is caulk the best solution to plug up the gap?

[Jay Miller]

Caulk works well for small cracks. Spray foam is better if it is a larger crack or gap. Once dried you can trim it and paint to match.