It's a question that's plagued cat owners and the whole of humanity for years, why do cats act so weird all of the time?. We know what dogs want, they like going on walks and being petted, but cats? they're much harder to understand. This Ted-Ed video goes some way to explaining their strange behaviours, including why they always have to scratch things, climb to the highest point they can find and fit into boxes and tight spaces at any opportunity.
A cats unsociable nature can be put down to the fact that they are actually solitary predators that use stealth to hunt and kill small prey which also links to the reason why they like to be high up - their ancestors used to look down on their prey whilst hunting. The video even goes on to explain why cats try and fit into every box they find. Well worth a watch.