Teargas? So how do the animals get out, assuming they did a halfway decent tenting job? My cousin had to have his house treated for some kind of boring beetles (log house), and they used formaldehyde, and there wasn't any kind of bug anywhere when they were done. The State EPA dude came and checked on them while they were doing it, too. They had a rig that recovered the gas after the treatment. It did/does not corrode anything, and left no residue on anything. Sounds to me like the commercial exterminator outfits are using a petroleum carrier insecticide is all. Shouldn't be corossive, but hard to say with certainty.
I had a big run in with Terminix and Orkin when I lived in NC. They did not want to kill "all" the bugs in my opinion. I guess they figured if they did that, I wouldn't need them anymore. I told them I would sign a yearly contract, but if I saw any bugs, anytime after two months, I wanted a full refund. They wouldn't do it. I went with some small local guy and was very pleased.
