Swarm

Swarm is an ability that boosts the power of Bug-type moves by 50% when the Pokémon's HP is below one-third of its maximum. This means that when a Pokémon with Swarm is low on health, its Bug-type attacks become significantly more powerful, allowing it to deal increased damage to its opponents. Swarm is particularly useful for Bug-type Pokémon, as it enhances their offensive capabilities when they are in a critical state during battle.