The lid must not fit tight enough for them to be able to get inside. Weight the lid down with something on top or get another container.
Em gave you some good advice. If the tote is stored inside, I'd also put some traps around it to get rid of the mice you have in your house.
Set mouse traps all around and inside the tote.
Peppermint & Cinnamon oil spray works wonders. I got mine at Ace Hardware.