Spider with prey

I saw this spider going around in circles. It would go around once and stop and kept repeating this action. At first I thought it was making a web but it kept going over the same area. When I took my attention off the spider for a few seconds it became obvious that the spider was wrapping up a jagged ambush bug. This surprised me because I had grown accustomed to seeing these bugs killing other insects and now the tables had turned. There was still some life in the bug but it could not free itself.