When attacked, they create an electric barrier by spitting out many electrically charged threads.
てきに おそわれると でんきを おびた いとを たくさん はきだして でんきの バリアを つくる。
Trivia
Due to a translation error, the English print of this card received an erratum to its Double Thread attack. The updated text reads: "This attack does 30 damage to 2 of your opponent's Benched Pokémon. Apply Weakness and Resistance."