OK, kind of freakin' out. A strange man entered my backyard.

[Scout1071]

Now, I should say that I live in an apt complex, but it's unusual in the fact we have pretty decent sized yards on the first level.

My back entrance is private. Someone just entered and walked about half way to my door, then turned and left.

Now, my good sense says he was looking for another entrance and got confused. It's happened before. After a few minutes, I let my mean looking boxer out to check the yard. He barked and growled and did a perimeter check then came back in.

But now, he is sitting at my door and growling more than I've ever heard him before.

What in the hell should I do? I have some friends in the complex a few buildings over. Should I ask them to drive by and check it out?