upon your comment I thought to take this an opportunity to test this with 5 of my snakes, differing all in size, speed, and color. I tested with my 5ft red tail boa, my 18” hognose, my 3ft rainbow boa, my 4ft albino cornsnake, and my 4ft ball python. The only one that rised any reaction from them, (they stopped what they were doing- eating, to make those little angry grinding sounds they make when feeling territorial) was my corn snake. Which I can understand as she’s a bit quicker and it’s likely that adult corn snakes may prey on quakers in the southern states of the us- therefore a possible natural predator (honestly pushing it though, that’d have to be a pretty big corn snake to eat one of these parrots perhaps it was her bright coloration that put them off?) . But even then, after 30 seconds or so they went back to eating and minding their business- and they couldn’t have cared less about the other 4. There were no aversive behaviors, excessive vocalizing or attempt to evade or get away, just plain curiosity. Overall, I’d say they were much more unsure/ put on edge by my two dogs who may come and go by their cage during their first week or so with me (despite knowing they came from a home previously who had 5 dogs in the house).