Heathcliff's claws are sharp enough to dig into drywall and plaster, enabling him to climb up walls ala Spider-Man. Instead of using this awesome ability to fight super villains, he pulls out a Zebco and ties a huge hunk of cheese to a string before letting it drop to the floor outside a mouse hole. Mr. Nutmeg says that it is something like fishing. The Pest Control man says that it's something like the most retarded thing he's ever seen.
The cheese's position on the floor is impossible, unless carpet has a current.