I have a 10 month old french mastiff. I'm wondering when and if he will be protective of my home? When I say who's here he perks up and looks at window and then comes over and sits by my legs like he is scared! He sleeps with me and not sure if Someone broke in he would do anything. At what age would he get protective? It's been 12 years since I've had a pup. And my last two dogs have been bullmastiffs...so I'm kinda new to this breed.he is a big pussycat. He is huge