It should be apparent by now the second cause of Spinarak's animosity, along with the general weakness of both her companions: Nelliel doesn't care for Pokemon Battling. She's just standing there. Watching, not unlike a spectator.

Spinarak screeches loudly and flails like a turtle when she's flipped over, trying to get back on her feet. Nel doesn't say a word, half in the battle, and half not.