Cats are many things; enigmatic, aloof, contrary and yes, they are also liquid. Pour a liquid into a container. It changes its shape to fill all the available space, before spilling over the top. Pour a cat into a container and it does the same. Need proof? Treat yourself and search online for ‘cats fitting into small spaces.’ Indeed, French scholar Mark-Antoine Fardin won the 2017 Ig Nobel Prize for proving that cats are mysterious substances with solidliquid duality.
They’re aided in this ability by their flexible spines, collarbones and shoulders, which allow them to squeeze into comically small spaces.