AT TWENTY past seven every morning, my dogs get restless. They get out of bed and start to pace up and down. Their agitation increases, minute by minute, and they glance around the room, trying to catch people's attention. Eventually, the excitement is too much, and they start to whine, and even to bark.

What's the big deal? It's simple: they get taken for a walk at seven thirty every morning. They enjoy the walk so much that they just can't contain themselves as the daily deadline approaches: the excitement spills out of them into the room.

Remarkably, the dogs don't just have the ability to remember the daily timetable; they can also recall regular events that happen on a weekly basis. Every Sunday evening, at 9pm, they are taken for an extra long walk to accompany a regular human visitor back to his own house. This week, our visitor was taken home by car, due to inclement weather, but the dogs didn't understand this.

As the clock approached 9pm, the two animals hopped out of their beds and began to circle the room excitedly. As the minute hand swept past the hour, the dogs began to whine. They knew, for sure, that it was time for the weekly long evening walk, and they were ready to enjoy it. In the end, I had to take them out for a long walk anyway: they were not going to settle down to their beds without it.

Dogs aren't the only ones to love a regular routine. There is something strangely appealing to humans about doing the same thing, at the same time, at the same place, whether it's every day, every week or even every month. There are many examples of this: having a cup of tea every day at 11am, going for a pint after work every Friday or even going to church every Sunday morning. Our bodies and minds are geared to appreciate the rhythm of regular events. It's as if biological systems tune themselves in to periodic happenings.

Many people find that they can take advantage of our inclination for regular repeated events as a way of achieving personal goals. For example, it's easier to do a daily exercise routine if it's done at the same time every day. I have an aunt in her eighties who has done the same twenty-minutestretch-and-flex routine at eight in the morning every day for the past twenty years. Her routine is as regular and predictable as a beating heart.

There are many natural examples of events happening at the same time interval: cocks crowing at dawn, animals producing young every springtime and birds migrating in the autumn. Animals may not be able to tell the time by looking at the clock, but they have plenty of natural reminders of the time of day or the season. We humans have become distanced from the biological prompts, but at some level, we must still be affected.

The short, darker days between November and February tell our bodies that we're in the thick of winter. The brighter mornings and louder birdsong remind us that spring is on its way. And the warmer ambient temperature and sunshine of those rare good summer days could only happen between May and September. At this stage in our development, humans are perhaps only aware of these things at a subconscious level, but for animals, it can be almost as important as if someone is giving verbal commands to carry out specific behaviours.

The egg laying behaviour of hens is a good example. We keep half a dozen hens in our back garden, and they lay eggs faithfully every morning, all spring, and all summer. As the shorter autumn days come along, a couple of the hens start to lay intermittently, skipping a day now and again. But when the short winter days kick in, the egg laying slows down, then sometimes ceases altogether.

When this first happened to us, we felt a little frustrated. We had begun to depend on our hens for those lovely fresh boiled eggs for breakfast. How dare they stop laying? After all, they were still happily scoffing the layers pellets that we so generously provided for them.

We decided to try an age-old remedy: we put a timed light in the henhouse, set to switch on at three in the morning. The plan was to deceive the hens' body clocks into thinking that we were still in the summer months, so they should continue to lay eggs every day.

The deception worked well for a while, but do you know what? We began to feel sorry for those poor hens. Maybe it was just our guilty consciences distorting our perception, but we were sure that the hens began to look tired and dishevelled. They didn't have the usual pep in their step. Yes, they continued to lay eggs, but they weren't the same vibrant, gloriously healthy birds.

We ended up turning off the timed light. We decided that nature's seasonal rhythm was there for a reason: the hens needed to have their winter rest. Just as humans need holidays, so hens need to have a break from the routine. Yes, we missed the daily eggs, but we learned that a bowlful of warm porridge makes a good alternative winter breakfast. And when the first eggs of spring were eventually laid, we appreciated them with renewed gusto. We found ourselves, like the hens, appreciating the joy of the regular rhythm of the seasons.

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- Pete Wedderburn