Swarm (ability)

Effect

Swarm increases the power of Bug-type moves by 50% (1.5×) when the ability-bearer's HP falls below a third of its maximum (known in-game as in a pinch).

Outside of battle

If a Pokémon with Swarm is the leading party Pokémon, wild Pokémon are twice as likely to appear.

Game descriptions

Ruby/Sapphire FireRed/LeafGreen Emerald	Ups BUG moves in a pinch.
Diamond/Pearl Platinum HeartGold/SoulSilver	Powers up Bug-type moves in a pinch.
Black/White Black 2/White 2	Powers up Bug-type moves in a pinch.
X/Y O.Ruby/A.Sapphire	Powers up Bug-type moves when the Pokémon is in trouble.
Sun/Moon	Powers up Bug-type moves when the Pokémon’s HP is low.

Pokémon with Swarm

#	Name	2^nd ability	Hidden ability
015	Beedrill	—	Sniper
123	Scyther	Technician	Steadfast
165	Ledyba	Early Bird	Rattled
166	Ledian	Early Bird	Iron Fist
167	Spinarak	Insomnia	Sniper
168	Ariados	Insomnia	Sniper
212	Scizor	Technician	Light Metal
214	Heracross	Guts	Moxie
267	Beautifly	—	Rivalry
313	Volbeat	Illuminate	Prankster
402	Kricketune	—	Technician
414	Mothim	—	Tinted Lens
540	Sewaddle	Chlorophyll	Overcoat
542	Leavanny	Chlorophyll	Overcoat
543	Venipede	Poison Point	Speed Boost
544	Whirlipede	Poison Point	Speed Boost
545	Scolipede	Poison Point	Speed Boost
588	Karrablast	Shed Skin	No Guard
589	Escavalier	Shell Armor	Overcoat
632	Durant	Hustle	Truant
736	Grubbin	—	—

Swarm as a hidden ability

#	Name	Other abilities
595	Joltik	Compound Eyes Unnerve
596	Galvantula	Compound Eyes Unnerve
636	Larvesta	Flame Body
637	Volcarona	Flame Body