Of all the animals on this earth, only human beings keep other animals as pets. None of the other animals keep pets. It sounds a bit strange but it is a fact.
Human beings keep many different types of pets, the most common ones being dogs and cats. Other pets include birds, guinea pigs, white mice, and rabbits. Then there are some really weird pets that people keep such as snakes and spiders.
Many house owners keep dogs to guard their homes as well as for company. I suspect the former is a more important criterion for keeping dogs. Dogs, being naturally inquisitive creatures, bark when they see something new or strange. They are natural early-warning devices. However, most dogs are friendly once they know that someone is not a threat. So it is common to see children and adults playing with their dogs. Their joy is obvious.
However dogs do need care. Regular meals, bath and grooming are essential so that they remain healthy. Otherwise, they tend to become mangy and surly. We can see this in the stray dogs that we come across sometimes.
Cats are natural predators. So they do keep the house they live in free of rats. However cats are not friendly as dogs. They usually keep themselves except when they want some attention.
My neighbor keeps pigeons. These birds are free to fly around as the please. They only return to their pigeon holes to eat and to spend the night. It seems easy keeping pigeons, but my neighbor says it is not so. Pigeons eat a lot. So he has to spend a considering sum of money buying seeds and peas for them to eat. There is another big problem with keeping pigeons and that is they leave their droppings all over the place. This is definitely a health hazard. I have mentioned this to my neighbor but he does not seem to care.
Another neighbor of mine keeps songs-birds. He has a couple of magpie-robins and about half a dozen of spotted doves. These birds can really sing. Every morning, their sweet singing wake me up. This is really a pleasure. I am sure my neighbor keeps these birds for the pleasure of their songs too. But like pigeons, they eat a lot and so this neighbor has to spend a large sum of money keeping them. These birds are not cheap either. They can cost hundreds of dollars each. Neverheless, my neighbor is very proud of his birds. It gives him pleasure and that, I suppose, is the main purpose of keeping pets.
I have seen people keeping guinea pigs, hamsters, fishes and rabbits as pets but these are not so common. Each animal has its special needs and not everyone knows how to look after them properly. I have not met anyone keeping snakes and tarantulas or other weird animals, but I have heard of them and seen them on the television. I wonder what pleasure they derive from these strange and dangerous pets. I wonder too how they look after them.
Anyhow I suppose each person has his or her won reasons for keeping pets, and as long as they look after their pets properly, it is all right.