My daughter's gerbil appeared to die when she picked him up, but revived when she put him down again. Could he have a heart problem? We haven't had him very long.

Mongolian gerbils can display a rather unnerving characteristic if handled roughly - they are likely to faint and may then appear to be dead. This is the most likely explanation for your pet's behaviour, and it's probably a good idea to restrict the time that your daughter handles her new pet. Gerbils don't like being closely restrained, and you may need to watch how she is doing this, to prevent a recurrence.

Although alarming, the gerbil will recover uneventfully if placed back in its quarters and left alone. This behaviour is a natural defensive mechanism, in the hope of persuading a predator to drop it in the wild. Cats for example are active hunters - they will often not feed on carrion.

By pretending to be dead therefore, the gerbil hopes to persuade its captor that it is not worth eating! With regular gentle handling in the home however, gerbils soon become accustomed to this experience, and will not react adversely to it.