Firstly, how do you find out which it is? Give it the benefit of the doubt, put it in with the gerbils and see what happens?
That's very kind and open-minded validating for the gerbilconda, but a bit shit for the actual gerbils, no? They have nothing to gain here and everything to lose.
Even if gerbilconda isn't going to eat them, from the pov of the gerbils all they know is it hasn't eaten them yet. They are never going to fully relax again.
So really, whichever way it goes it's all a bit shitter for the gerbils than pre-anaconda.
Whereas for gerbilconda it's quite the opposite - if they are genuine they get the lovely validation of being with their gerbil peers. And if they are not genuine... well.
So really however it goes, and however genuine gerbilconda may ne, the gerbils are still getting a pretty clear message here about the relative value of gerbil interests and anaconda interests aren't they?
And finally...
Do you believe an anaconda could really be a gerbil on the inside? Not just for the purpose of this analogy, but as something that could actually happen? Maybe due to a surge of gerbilesque hormones mimicking gerbil development?
Or do you think that's ridiculous? Impossible? Laughable?
Yet you happily believe it's possible when it comes to humans being "really" the opposite sex on the inside. Hmm.