My first boy was a car chaser, well, anything that moved chaser, be it mechanical or biological, ok, even dead leaves blowing across the ground would catch his attention for at least a moment. Current guy doesn't really care about cars too much (unless they need muffler work). I live near an Airforce base so we have low flying planes going over all the time, he doesn't care. I also live near a highway. Last week I heard what I thought was just one of the trucks going by on the highway but the noise (thump,thump,thump) just kept going. Finally, I decided to go out front (Arleigh was out back) to try to find out what this noise was. It was coming from the neighborhood side not the highway, so I have to walk around back to see that it is a helicopter hovering about 500 ft. above the houses about a block away. What's Arleigh doing…looking up into the hickory tree into which a squirrel has run. Couldn't care less about this extremely loud hovering thing. Don't know why it was there, had no markings other than the tail numbers, and it flew directly over the back yard a couple of times only to hover again in the same spot. No reaction from Arleigh except his normal "Well you're out here, let's play!" Silly dog, the humans were all coming out of their houses to try to see what was going on and he was being....well... a Basenji.:)