1. They are early risers... and no I don't mean the 6:30 am on a weekday types. I mean four am on Saturday and Sunday types. There is only one word for this type of neo-insomniac behavior: insanity. Pure, un-filtered, and un-conjugated insanity.

2. They really want to buy what you don't have for sale. For example: the tables on which your items are sitting, they want to buy that. All your clothes hangars (but not the clothes) they want those. The spare tire to your truck, spare yard chemicals,  that special item you received from your now-dead great grandmother... they want all of that.

3. Whenever you advertise your sale to begin, they will show up half an hour earlier. It doesn't matter if you say your starting at 1 am on Sunday... they will show up at 12:30.

4. They say what they think. It's a beautifully double-edged sword. If you have something they want. You'll know. They will shout it from your rooftop about how much they like thing X or thing Y you have for sale. And, conversely, they will let everyone present know how your lawn mower is a giant waste of iron. They will say things like, "Who would ever wear these clothes out into public?!" or, "That antique hutch is disgusting!" or, "That wedding dress is an evil curse to anyone who would wear it." or, "These baby clothes look like they once clothed an ugly baby!"

There you have it, four things you never wish you didn't want to know about garage sale go-ers. So next time you have a garage sale or yard sale, be ready. Have a thick skin and plenty of coffee. When you're done, have the Salvation Army come pick up all that's left an not junk. Then have the junk hauler come and take all the stuff that is junk. Go ahead, laugh. But when you're dragging like a wet bag of hammers getting all your precious items critiqued in the most painful way from 6-11 am on your day off, you'll think, "I should have listened to the Yard Whisperer."