My only addition to what Brad said comes from my experience as a bird owner. You need to be careful with Febreeze, as it has been known to harm birds and other critters when sprayed in their cages or into the air directly around them. I've used it on my carpets safely, but keep it out of the immediate area of birds, herps, etc. And stay away from the new gadgets that spray it (or any similar products) into the air on regular intervals.
I use scented candles on a regular basis with no ill effects to birds or herps, and have used the oil and gel based plug-ins with no problem.