My dogs are on oral Rx medication for fleas and it's totally effective...no fleas ever since. Before that, the stuff you dab on their coats externally were not totally
working, & I have quite a few snakes...having my house infested was NOT an option.

My question for the pest control company is what if you have birds? Does the 4 hour removal for safety still apply? Birds are more sensitive...as are reptiles...to the
sort of things they'll use on your home. They may not know or care if any harm will come to snakes, but they should be able to tell you if it's safe enough for birds
after 4 hours. If it won't harm birds, it should be safe for snakes.

I would be inclined to keep my snakes away for at least a day anyway, and I'd do as I've done for emergency power outage during an ice storm*. Maybe you can
keep them at a friend or family's location for just a bit? *bag each snake in secured (!) pillow case, & put that into an "ice chest" (or styro-foam box), with a jar of
hot water for warmth; change the hot water about every 8-9 hours...they'll be just fine.