I Live In Las Vegas, NV, First Of All Where

I live in Las Vegas, NV, first of all where few bugs live, especially in the summer. I feel bites on my skin and don't see any bug. I feel the bites when standing in grass but I also feel them in my house, especially when in bed. I feel the bite-like feeling, and it itches but no bite mark. I keep a clean house and have sonic bug repellers throughout my home. Could it be something internal?