Yep, can't take eyes off of turtles or tortoises. They can disappear in a split second. Just have to keep looking. Get on hands and knees and feel every inch of your yard. Don't just look, feel. He will blend in to well to just look. Also, if you don't find him before dark, be sure to look first thing tomorrow when the sun is nice and bright and hot, hopefully you will find himself basking. Good luck, I sure hope you find him.