The relativistic cage paradox

I notice a website where they talk about the relativistic cage paradox.
And it says: "If the animal is smaller than the cage, it can be in the cage; but if the cage is smaller, it cannot be in the cage."
This ties in with the paradox of the train and the tunnel.
But what is very interesting is that lots of people, each as uneducated as the next,
want to give their opinion.
Most admit that they don't understand anything (they are the most honest) and a few attempt explanations that are often stupid.
It's obviously very saddening, but not so much to see idiots talking stupidly, no.
The sad thing is here, on the Usenet forums, in the sense that we are going to spit on the geniuses (let's not be vulgar and disastrously humble) who know how to respond, with unequaled precision, beauty and logic.
This is saddening.
R.H.