Many people have experienced the embarrassing moment when their host’s male dog has suddenly clasped its front feet around their leg and started making vigorous pelvic thrusts.

Why do these dogs embark upon such an unpromising activity?

The answer is that dogs pass through a special socialization phase when they are puppies, during which time they establish their identity. This critical period lasts from the age of four to twelve weeks, and any species sharing this time with them in close and friendly proximity becomes their species. For all pet dogs there are always two species present during this crucial stage of growing up – dogs and humans. As a result they become ‘mental hybrids’, powerfully attached to both species. For the rest of their lives they remain at ease in both canine and human society. The members of their human family serve well enough as an adopted ‘pack’. Humans share their food, share their den, go out patrolling the territory together, play together, indulge in a little social grooming, perform the required greeting ceremonies and generally act the role of dog companions with alacrity.

Dog society and human society make a good match. Only where sex is concerned does the relationship break down.

Fortunately, there are some powerful inborn responses involved in canine sexual attraction, which usually serve to keep dogs aimed in the right direction. Since humans do not possess the dog’s particular erotic fragrance, they do not normally trigger the sexual responses of the male dogs that share their homes. As far as the dogs are concerned, people are simply ‘members of their pack who are never in sexual condition’.

All should be well but, sadly for most male dogs, encounters with bitches in heat are abnormally rare events in their domesticated lives. A level of sexual frustration builds up where even the family cat begins to look appealing. At this point a randy dog will try to mount almost anything that will stay still long enough, including cats, other male dogs, cushions and human legs.

Human legs are attractive because they are easy to clasp. The choice of a leg rather than some more appropriate part of the human anatomy is due simply to the awkward, undoglike shape of human beings. They are too big and too tall, making the leg the only easily accessible region for a last-resort sexual advance.

The correct response to a leg-clasping dog is compassion rather than anger. It is we, after all, who have condemned such dogs to an abnormally celibate existence. A polite rejection of their advances is all that is needed, not the angry punishment that is sometimes meted out.

The comment about the dog’s interest in the family cat was not intended to be facetious. Some sexually frustrated dogs do try to mate with cats, but this only happens when the animals concerned grew up together as puppies and kittens. A close relationship with young cats during the critical phase of puppy development simply adds felines to the category of ‘my species’ in the canine mind.

A puppy that has played with:

(a) other puppies in its litter,

(b) the family kitten, and

(c) its human owners, during the socialization phase of four to twelve weeks, will have a triple attachment that will last a lifetime.

There is another side of the coin to this attachment process. The absence of a species during the socialization period in the puppy’s development will mean that it is automatically something to be avoided later on. This applies even to the puppy’s own true species. If a tiny pup is taken away from its mother before its eyes and ears are open – say, when it is only a week old – and hand-reared in isolation, it will become massively attached to humans but will always be shy with other dogs in later life. It is therefore a great mistake to remove a puppy from its family too soon. If there is a disaster, with the mother dying and only one puppy surviving, for example, then it is important to try and have other puppies or dogs around the young one as it is being hand-reared, so that it becomes used to the company of its own kind during its critical growth period.

If a puppy is left in the company of its own canine family but kept completely away from humans until it is past the age of twelve weeks, it Will never become tame and friendly with people in later life. Puppies reared in a field on an experimental farm, where they had no close contact with people until the litter was fourteen weeks old, were effectively like wild animals.

The idea that the domestic dog is in some way a ‘genetically tame’ animal is therefore not true. The suggestion that wolves are more ‘savage’ and untameable than dogs is also incorrect. A wolf-cub taken at a young enough stage of development becomes a remarkably friendly companion, so much so that most people, seeing one being taken for a walk on a collar and lead, would imagine that it was just another large dog. Indeed, on one occasion a tame adult wolf was taken from England to the United States on the Queen Elizabeth, registered as an Alsatian, without causing any comment. It was given a daily walk around the deck and was cheerfully petted by passengers and crew, who would have been horrified had they known its true identity.