They have lots of safe paces in the house including a giant cat tree with multi- condos in it. It happens at all times of the day and night . . . no particar pattern. That's why it's so frustrating, because I can't figure it out. I work with horses that have behavior problems. How I wish cats were as uncomplicated as horses. Cats are true mysteries which is why I adore them so much!

Thank you for your kind concern. :")