Our 16 month old terrier occasionally messes in the house at some point between us going to bed and waking. She has a crate which she automatically goes to when we go to bed, but we leave the door open and she often moves to a spot at the bottom of the stairs. DH is wondering if we should close the crate at night but I'm not totally comfortable with that (definitely not in hot weather as she needs to spatchcock herself on the tiles). Like I say - it's only occasional - maybe once a month / 6 wks - so is it just fairly normal young dog behaviour rather than a problem to resolve?