I learned that term from someone who'd put the gerbil cage on a table in front of the grooming table while grooming her Airedales. It's an excellent method of keeping the dog on the table, attention focused forward.
There are two terrariums in my house, one with Matilda the cornsnake, the other with Chilly-Billy the leopard gecko. The Airedale with the low prey drive, Darwin, likes to stand and stare at whatever is or is not happening inside. But now with crickets still chirping in Chilly's tank, Darwin wanders over several times a day and just stares with great concentration. I'd like to know what's going through his head--if anything.