The laser system has promise, but you need a source of random data to drive the movement of the laser pointer (maybe strap them to other cats?). Otherwise, an attacker who can predict the movement of your pointers may be able to predict the output of your entropy stream after observing the behavior of your cat colony (certain cats may prefer to hunt at different times of the day, or prefer to lay in wait and pounce vs giving chase, etc).

Alternatively, you could observe a field (bed) of cats and record their chirality, assigning 0 to sinistral cats and 1 to dextral cats. The science[1] seems to indicate no preference for one or the other per cat, so your readings should be random. However, you may only observe one or two bit-flips per hour and during transitions it may take some time for the system to settle back down to a steady-state.

[1] http://blog.dimview.org/math/2017/07/28/cat-chirality.html