Generally, the dogs bark when someone comes near the house. Today, this was some people walking, two with a dog on a leash, someone canvassing (I assume for political stuff), someone who left a flier in our door, someone who left a menu in our car windshield, and every time the AC kicked in or a loud noise came from the alley. Since we don't have a doorbell, the dogs suffice to let us know when someone is here, but generate too many false positives.
Ahfu barks from the couch, looking outside and barking at any of these things. If it's the AC, then he barks a few times, realizes there's no one out front, and stops barking. Widget, however, loses his mind when Ahfu barks or he hears the AC kick in. Or any other thump from the alley out back. In fact, after three hours of measuring how much he barks on my iPhone, I would say it was about 38 minutes out of a 2 hour period. The longest span was about 9 minutes, with averages at about 3 minutes.
The saddest thing, however, is the result of wondering what Widget does when he barks. I followed him around and I found out that he doesn't know, either. In fact, long after Ahfu has stopped barking, Widget continues to bark, often at the wrong windows, if not in the middle of the living room, barking at the ceiling, looking around like he's trying to find something to bark at.
When takayla is gone, Widget sometimes howls, too. He's small, so his howling sounds like a long distant coyote (pronounced "ky-tee-ho-tee" in our house, because CR used to say that when he was little due to his See-and-Say). He howls more at night.