Not a question that may have ever kept you up at night, but it might now, when you consider how much more interesting the show would have been if it had been about cat problems, and not cat people problems.
In this video by Animation Domination, we see what would have happened if Lion-O and team behaved - and had the physical characteristics - of real cats. Stick around. You might learn something. About pointy cat dicks.
SCIENTIFICALLY ACCURATE THUNDERCATS [Animation Domination, via Laughing Squid]