If you rattle someone's cage, you do something to make them angry, often on purpose.
I wouldn't approach John at the moment, someone's really rattled his cage this morning and he's in a horrible mood.
Why are you so cross? Who's rattled your cage today?
My girlfriend deliberately hid my car keys so that I wouldn't go out with my friends – it's really rattled my cage!
Don't confuse it with
If someone feels caged in, they feel confined to a small space.
This flat is far too small, I feel really caged in.
I don't like travelling on the tube during rush hour – you feel so caged in.
Thai police found six tigers in three cages on the rooftop of an apartment block near Bangkok, this week. Tiger trafficking is a problem in Thailand, where the animals are illegally sold for their skin, fangs and organs, which are used in medicines. The animals are now being looked after by a government wildlife facility.