I have been to many houses to collect iguanas which have lived at almost complete liberty in the living rom for most of the day and evening. The room has been kept really warm, 26 degrees or more, and the iguana was usually to be found stretched out along the settee, or perched on top of a cupboard.

In every case, the family was distraught that their pet was leaving them, but usually they had little choice. It had become just too big and aggressive to cope with. What usually happens if the iguana is a male is that it takes over the family and rules the roost. He clearly sees himself as the "top dog" so to speak.

In reptile hierarchies there is no such thing as democracy. The "top dog" rules the roost (to mix metaphores). What I find truly amazing is that iguanas, which are cold-blooded reptiles, can detect, probably by smell, who is male and who is female in a human family and react accordingly.

They also react in a specific way with the adult female members of the family at different times of the month. When this is combined with aggressive biting or tail-lashing toward the adult male humans, then the difficulties quickly become obvious.

Of course, these difficulties shouldn't necesarily put you off. It's all part of what pet-keeping is about, after all.

Iguanas will readily eat foods which are not good for them. This will cause nutritional deficiences which may not become apparent for a couple of years and then will be extremely hard to remedy.

Foods which should be fed frequently to an iguana include:

• greens like broccoli
• dandelion leaves
• certain types of cabbage like kale

Foods which should never be fed because they are too high in protein and/or fat are:

• meat
• mice
• dog food
• cat food
• iceberg lettuce should not be offered because its nutritional value is not high enough