Pokémon FireRed and LeafGreen/Diglett's Cave

This underground cave connects Route 2 and Route 11. It's full of and. They both have Arena Trap, an ability that doesn't allow you to escape from battle. If you want to avoid battles, pack a Flying-type Pokémon first in your party, since Arena Trap doesn't affect Pokémon immune to Ground-type moves. You can also use Repels, however, it only repels Pokémon that are at lower level than the first Pokémon in your party.