Rats, cockroaches, ants and wasps might be household pests to many of us, but to a group of enthusiasts, they are liked, if not loved, as pets.

Perhaps the easiest pest pet to relate to is the rat. In the wild, these rodents are dark, dirty and riddled with germs. But varieties have been bred which, to some, are attractive to look at and can be taught some simple behaviours.

The Norway rat is a pest across the whole of the UK, and indeed much of the world. Highly adaptable and quite intelligent, it often lives off the waste that we humans create. Rats are extremely social animals, preferring to live in colonies where they also breed very quickly.

It’s the intelligence and social qualities of rats which some believe make them ideal as pets. They can be friendly animals, responding well to attention, and enjoying the company of their owners.

But while they might be much cleaner than their wild relatives, they share the same traits. Rats can be extremely destructive, chewing their way through many materials. They’re also nocturnal, preferring to be active in darkness, and they don’t live for very long.

Insect pests can also be a form of pet

Cockroaches, ants and even wasps are bred in captivity, either by insect-lovers or as a source of food for other creatures.

This is sometimes the fate of cockroaches, which can be kept as live food for reptiles. Cockroaches are chosen because they are very easy to breed and will eat almost anything.

Not all species of cockroach are thought of as a pest and some of the more exotic varieties are kept as pets in their own right. Madagascan hissing cockroaches are popular because they make a noise, while giant cockroaches make for a curiosity.

Every cockroach breeder, particularly those keeping the common German cockroach as reptile food, must take care that the creatures don’t escape. Outside a controlled environment, their rapid breeding cycle and adaptability can quickly create a pest control problem.

Ants and wasps as pets not pests

Many people are fascinated by the complex structures and societies built by social insects such as ants and wasps. As a result, some choose to keep them in captivity, to see how they live.

No insect display in a zoo seems complete without a colony of leaf-cutter ants, who slice up vegetation and carry impossibly large pieces back to their nest. Many ant farms kept in homes are less ambitious, with the highlight being the view of the complex web of tunnels, exposed by their being kept in slim glass-sided tanks.

Not surprisingly, keeping wasps as pets is much more unusual. It requires a lot of space and strong nerves, but these requirements don’t deter a dedicated bunch of enthusiasts. They venture out to find young nests in the spring, and relocate them to a purpose-built enclosure. Here the wasps have space to fly, and are supplied with a steady source of food.

Despite their captivity, the danger of these pets becoming pests never goes away. The creatures are always looking for food, and will exploit every opportunity to escape. It doesn’t take much for pet control to become pest control.