I had someone in my backyard about 6 months ago (I have moved since then and havent had any problems since) so I know what this feels like! Luckily I have a German Shepherd that secretly is my big baby boy but he is very protective of me and especially since it's only him and I in my house. We were inside and I couldnt figure out why he was pacing around the place so I let him out the back and I couldnt believe the noise when the 'intruder' figured out he had company . There was a crash and a bang as he jumped the fence and of course my boy was making quite a bit of noise himself. I did that 'sneaky tip-toe hiding in the shadows' walk while I figured out how it was all gonna work out but thankfully whoever was in the yard didn't stick around. I trust my boy with my life. He wouldn't hurt a fly unless of course someone was seriously trying to hurt me......If I didn't have him I'm not to sure how I would react to something like this though and especially considering I live alone!!