HELP ANT KEEP GETTING IN MY BABY'S CRIB

Everyday I clean my baby's crib and put any meds in the floors and windows. I have to change the sheets everyday and her blanket I also wipe down her mattress and ants still go inside her crib. I don't I don't know what else to do. There is nothing in there that would attract them why do they keep coming and how do I make them stop