In the past, our queensland/beagle/pitt boy (neutered, of course) has been pretty defensive of our property - once someone crosses "the line" (comes thru the gate) WITH NO FAMILY MEMBERS present, he gets very defensive (well, actually, he's been known to bite - so far no skin broken - he's 11 yrs old). Should I be concerned? We live in an area where we have a few local "tweakers", and I feel he's been a great deterrant. However, he bit the pant leg of my daughter's boyfriend ((she's old enough to have one!) (granted, it was at 11pm @ night)). This dog has seriously prevented "undesirables" from coming into the yard. He does his job well. But I really don't want him to get into trouble for doing his job. Can he, if he's in his own yard? Do I need to keep him inside @ night/ He's also really good at killing rats and skunks . I have a sign that says "Dogs in yard". I've heard that if the sign says anything about "Beware" , then you're liable.