I was on patio observing unusual chem trails when i observed a dark round object beneath one of the chem trails. at first i thought that it was a vulture, but it wasn't moving and it was too high in the sky. i saw it move in and out of the chem trail but for the most part it was just hovering around the trail cloud. i took a picture of it with my iphone and enlarged it to get a better view. it appeard to be somewhat disc shaped. in a few minutes it just disappeared. then a saw a small jet traveling at high speed in the direction of where the object had been. the jet continued north until it was out of sight.