Why do we hear coyotes and wolves howl or yelp while house dogs more often bark? Does it have something to do with living in a pack vs. living alone? Also... today when I was on a walk around noon I spotted two separate coyotes (the dog I was walking started barking at the first one which got me thinking about my previous question). I thought wild dogs were nocturnal. Is that incorrect? If it is correct, could their day-time roaming have something to do with the noisy humans keeping them up? Thanks!