Somebody dumped these two in a nearby park. My wife found them this morning while on a walk so of course we brought them home. They're both social, flea-free, and still had full bellies so it much have just happened. We've got a pretty full house already so if anyone happens to be in the socal area and is looking for a pair of happy little voids, let me know!
Not sure how old the program was OP watched but they found one void in 2017 using cosmic rays. I'm guessing the pyramids are way too solid for ultrasound or x-ray to work.
https://www.science.org/content/article/cosmic-rays-reveal-unknown-void-great-pyramid-giza