Instead, it knocks the intruder over with its massive size and pins them to the ground, or, will simply stand in front of the stranger or intruder and refuse to let them pass. Bullmastiffs become intensely attached to their families and do best when they can live inside with them.
The Bullmastiff gets along well with children and is very loving towards them. Parental supervision must be maintained when they are with children; they may knock smaller children down accidentally because of their large size.