It is because he is switched on at night. It is as if someone switched him over from domestic to wild. This is because he is programmed to be active at dawn and dusk (crepuscular) and throughout the night, depending on the individual cat. Domestic cats don’t regard night as sleep time. They see it as kill time. Active time.
When a sleepy domestic cat is activated like this he may come in from the outside in a hyper state carrying with him not a mouse but the mentality of his wild cat ancestor sloshing around the brain.
This is the “hyper” behaviour you are referring to. Also it is likely that he met some wild animals outside which would have wound him up from sleepy domestic to highly strung wild cat. In Jackson Galaxy language he has his Mojo at max volume.
If he is a full-time indoor cat it is far less likely that he’ll become hyper at night but distinctly possible. My assessment of that is that he’ll be activated to hunt and be more active but have no where to go. A conflict arises. He’ll be driven to walk, stalk and hunt prey but there’ll be no prey, just carpet and furniture. He may run around and demonstrate pent up energy without a way to release it.
This is where you’ll have to play with him which is impossible at night because, guess what, you’re asleep or trying to get to sleep while your little fella wants to do the exact opposite.
This is one aspect of the human to cat relationship which is uncomfortable, in truth, for both parties. Domestic cats are out of step with humans in this regard. In general (and there is plenty of flexibility) they are active at night and sleepy during daytime. We are the opposite. A lot of cat owners struggle with this and find it hard to accept.
A lot of full-time indoor cats squash this desire to hunt at night because they have to. They fit in with their human companion’s body clock. They sleep more. This is a reason why cat owners ask why cats sleep so much. Normally they would not. They don’t have any way to expend energy. They kill time instead. It is a failing in the relationship.
The problem goes back to that eternal discussion between allowing cats outside or keeping them in. Americans are by far the biggest exponents of keeping cats inside. Some insist on it and I totally understand why. It is much more safe for cats and wildlife. In Australia, some local jurisdictions have cat curfews. They can’t go out at night to protect wildlife. Great for wildlife, but totally out of step with domestic cat behaviour and desires. Once again this is a sign of a failure in the domestication of the cat.
There are no simple answers. I remember a man in America (I won’t mention his name) who vehemently insisted cats stay inside. When I suggested otherwise he became livid and ranted and raged at me. Blind arrogance in the certainty of his correctness. He was looking at the problem from one standpoint: himself. He did not want his cats wandering around outside bringing in prey and causing a disturbance and a mess at night. He wanted his cats to be safer too but the prime reason for his fixation on keeping cats in was his life. His cats were terminally bored. I felt sorry for them. I hated him.
This is where a nice catio or backyard cat enclosure can help. A neat compromise. But it is very much a second best. Note: I am not recommending cats be let outside to roam freely. It is a personal choice. I am just saying that that is where cats want to be at night.
P.S. “Him” also means “her”. I want to be gender neutral but can’t use the word “it”.