Question – are there any kind of household products that would either kill or incapacitate a snake? Like, could I pour some bleach or Drano on it, and slow it down, just long enough to go out and grab the shovel from outside? Or squirt it with hairspray, or WD40?
Dude, I closed the article after the first picture. That was a little too much.
The aerosol blowtorch method worked fine for Roger Moore. 
Don’t kill it! You do need to make real sure it’s gone (or was never there).
Here’s a couple of ideas.
If you done mind a bit of mess, sprinkle flour or baby powder around the basement floor, especially doorways and close to walls. You’ll know in a day or two if you have company down there. This is how my friend kept track of a missing boa until he caught it. Btw, I actually found it for him by heading straight for the refrigerater. Sure enough, he was curled up between the fridge and wall where the motor was keeping things nice and toasty.
The other idea would be to get your hands on a video baby monitor or security camera, the kind that records when there is motion.
DO NOT go poking around! A camera on a broom handle might help for looking onto corners and under things but a big rattler can move extremely fast and a poked snake is a pissed snake! Better to try the non-invasive stuff.
It’s easy. Send in my 3 dogs. Wrigley is stupid but with matted fur fangs can’t get thru. The Girls will kill it while it tries to untangle itself. They don’t eat their prey, but there’s lots to eat on a snake. I’ve heard it tastes like snake.
Aren’t baby monitors almost as nasty as adult monitors?
Oh, it’s not over. That snake is still in the house.
You trying to rattle the OP all over again?
mmm
Oh, I dunno about that! I knew a Savannah Monitor that thought it was a dog. Vanna the Savannah used to belong to my friend Linda, who kept little Softclaws caps on her claws and generally gave her the run of the place!
Silver Spring woman was recently bitten by a venomous snake — in her bed
"The snake in Christie’s bed was a copperhead, which seldom get longer than three feet. But it was big enough. It had bitten Christie — twice, it turned out. "
Silver Spring, Md
So robz2 what are you and/or your daughter going to do to assure her that there is no snake in her house?
I searched the basement, her husband has searched. We moved boxes and shelves, the washer & dryer. Her dogs have been all over the basement. They left for vacation for a week. When they get back I will tell them to do the baby powder trick and see if they find anything.
Do you have a key to her place? If so, do the baby powder thing now; that way when they return, it’ll either be undisturbed, so no worries, or they’ll know they’re dealing with this.