Is anyone having this trouble? Involving the hamster and sim mastering sleep standing.

I'm having this bug, both the sims freezing after interacting with the rodent and the game freezing after deleting the cage problem.

On Q&A forums there is a workaround: If a famous sim donates the cage it disappears without causing a freeze. This requires GF and a three star celebrity with a good reputation. I haven't tested this, but maybe it helps somebody.

My own workaround was to move all furniture from the room with the rodent into household inventory, except for the cage. Then delete the room in build mode. Afterwards I put everything back where it was and the game didn't freeze. Obviously this works only if you have very simply furnished rooms that you can quickly re-furnish. (In my case it was an apartment kitchen.)