We have two dogs, both are rescues from a shelter. One is a 7yr old miniature Schnauzer who is deaf. The other is a mixed terrier pup who is about 2yrs old. The pup seems to have an 'on/off' switch for misbehaving. What I mean is that one minute he's as calm as can be the next he's going after the older dog, grabbing his leg(s), head or wherever. Trying to calmly correct him with the 'NO' command doesn't work at all. In fact after several times he'll start barking at us and won't stop until he's ready to even though we calmly tell him 'NO' or 'Quiet'. He doesn't do this all the time it just seems like certain times of the day such as around 6pm when we're getting ready to eat. We're not really sure what to do with him. Most of the day he's really good, it's just at certain times it's like a switch is thrown and he goes from 'Good Ozzy to Bad Ozzy'. He does love his carrots and green beans. If we can get him to stop going after the other dog should I reward? We're also wondering if he's just bored and wants to play but is too rough.