I AM not a very typical human animal and have rather unusual nocturnal habits. I always work through the night, with something of the excitement about staying up that one feels in childhood. Even if I don't have anything to do - which, as a workaholic I find deeply unfulfilling - I still stay up until around 4am. It's the most peaceful time in my study with no fuss or drama except that taking place in my aquarium.
My wife and I do not sleep together. We are both only children and feel that sleeping is something we do best alone. No other species sleeps together in bodily contact, unless to keep warm, and it's something I don't find attractive. I think we have the ideal arrangement - we have separate bedrooms joined by two big folding doors that we can open if we're feeling sociable.
This also means that we do not confuse sleep with sex. I find the phrase 'sleeping with someone' very odd: to me they're rather different activities and the idea that sex becomes an accessory to sleeping belittles it. I mean, you don't eat just because you happen to be in the kitchen, do you? Dinner - and sex - should be an event.
I rarely have any difficulty going off to sleep. I think the key is never having anything to do with work in my bedroom - books of any description are banned. But I absolutely must have four down pillows - I make myself a nest with them like an ape. I will never return to any hotel that has those awful bouncy foam pillows. I also like a very large bed - mine is 7ft by 7ft - because I don't want to feel the edges of it. I don't like a narrow bed and I don't like a narrow life - as I have shown by combining zoology, painting and writing in my career.
When I was a teenager I decided that sleeping was a terrible waste of time and stayed up for 36 hours. I wrote down all my experiences in a sort of teenage way - poetry and so on - but I felt so awful that I didn't repeat it. I think dreams are a device to keep us interested in sleep - mine are always very entertaining with wonderful plots and I hate waking in the middle of one.
We are very vulnerable when we sleep, which is why, since the human dwelling was invented about eight and a half thousand years ago, the bedroom has always been the most secluded and private area. Because we make love for so much longer than our fellow primates - an ape averages about eight seconds - we tend to do that in the safety of the bedroom, too.
Though I write about typical human behaviour I am actually a loner. Working with a television crew satisfies my need for group- based activities and I rarely socialise. When I'm with other people I do sometimes smile to myself when I observe very obvious signals.
In my dealings with my son and my wife, however, I have very deliberately avoided using any sort of intellectual analysis. These are emotional relationships which are dominated by that powerful biological mechanism - love.
No other species has such a prolonged parental burden as we humans. The pair bond that we establish should, ideally, last a lifetime because we are needed as grandparents, too. The church makes a huge mistake in saying that sex is only to do with procreation - it is a pair-bonding mutual reward system which ensures that love thrives. It is very important to me.
My own pair bond has lasted for 42 years now, surviving various threats, including the compulsive lechery that explodes in our early forties. Fortunately, in my case, work became my mistress. I sat down and wrote The Naked Ape which, much to my surprise, became a bestseller and changed our lives forever.
Dr Morris's latest television series, 'The Human Animal', begins tonight on BBC1 at 9.30pm.