Why has my cat suddenly stopped using the litter box? How do I keep my dog from digging? I don’t want to confine my dog all day, but when I leave him out he chews EVERYTHING. Even the most patient pet owner can end up at wits end by a behavior problem like marking territory, or aggression. We suggest calling our behavior helpline (444-7800 ext 221) for advice from our experts on specific problems you just can’t live with or email bhelp@nehumanesociety.org. You can also check out our archives of articles for advice and ideas on beating the behavior blues.