I find a 40 watt piezo tweeter sweep pulse driven in the 18.5 Khz to 40 Khz range to be an effective deterrent to most of the pests in a standard size dwelling space (living room or master bedroom size area). Set the frequency sweep at about 2 seconds duration and the pulse interval to 15 seconds or so, and the little critters (medium small rodents up to moths and mosquitoes) will vamoose and stay out of range. 40 watts seems to be just enough to penetrate most gypsum/panelboard interior walls within the distance range limits of the tweeter. It really messes up bats in the area; a certain no-fly zone.