I have read from several sources that 1 out of every 1,000 (random statistic but you get the idea) G. rosea have a really nasty temperament. Regardless how you care for them, they are going to flick hair, and bite every chance they get. And some people call them "psycho rosies". But yes normal G. rosea can be unpredictable I suppose. Mine is usually VERY docile. Out of having her for over 10 years, only once has she flicked hair, and only once has she threat postured, and one time she actually bit the paint brush I touched her with, WITH OUT flicking, or posturing first. So even though she has only been aggressive on 3 occasions, out of 10 years, I always do a standard temperament test with a paint brush before I consider handling.it's not that they're phycho it's that their unpredictable, at least mine are i have one that webs everywhere and if you touch her web she postures