Dragosani did not know how or why the male rat had died.

It's one thing to look at erections in male rats, he said.

When researchers gave male rats estrogen, they showed less damage, he said.

But in other circumstances, a shot of oxytocin will cause a male rat to walk away from a potential partner.

The show also included a grey male rat which he had bought from Harrods.

They were with Toxie, another young male rat, who was good at reading and acted as a kind of assistant.

The juice of the berries have been tested in male rats and are reported to be safe to consume.

The male rat at once sprang upright, its pink eyes wide in terror.

Researchers have found preliminary evidence that fluoride causes cancer in male rats, Federal officials said today.