You shouldn't leave your food laying around.
Sally just finished a late meal at her kitchen table and has leftover food.
Sally wants to go to bed.
Sally puts the food in the refrigerator before going on to bed.
Sally leaves the leftovers out on the table and heads to bed.
Sally warms up the leftovers for breakfast the next morning.
Sally gets up in the morning to find ants crawling all over the food.