A mystery and an observation

Nano the Beagle / Rat Terrier mix can't hear me yelling at him from 10 feet away to come inside, but he can hear a piece of pasta hit the floor on the other side of the house, from upstairs, through three walls and the floor. I wonder why that is.

Nano also knows the sound of a jar of peanut butter opening. I was making a couple peanut butter pies on Sunday and he was upstairs. I opened the jar of peanut butter and he came running. Nano is spoiled.