Of course, animals are conscious and enjoy things and feel pain too. Just less intelligent and with less language ability than humans. Chimps and dogs certainly understand humour. I wouldn't be surprised if elephants do too, being social creatures.
It goes beyond humour, you can see it in a lot of scenarios and it ruins politics. There are people who appear literally unable to consider hypothetical scenarios. Not in a nasty way, they're sometimes wonderful people to have on hand. They simply only deal in reality as they see it. You can walk them slowly through a "and what if ... happens?" and they can't do it.
So if you're not able to make the right mental context switch at the right moment, you won't get the joke.
All humor? (Honest question)
I was under the presumption that e.g. slapstick or schadenfreude humor doesn't need linguistics, and is therefore seen in many animals. Animals that don't have any form of language but do have rather intricate social systems or even ranks and caste systems. but do have humor. E.g. where breaking or pushing those systems is the humor.
E.g. "boss gorilla slips on a banana peel haha".
Yeah. I don't blame her for getting mad.
Human intelligence is defined by behavior we humans value. Intelligence tests are geared to measuring these aspects.
Intelligence tests devised by animals would look totally different - and it's quite thinkable humans wouldn't do too well taking them.
Wouldn't assume that animals have less language ability than we humans, unless we totally figured out what other species are really talking about. Unless we do this is just an assumption.