You know, I can’t remember the last time we had tortoises in the How2 studio. It must have been years ago. And how do our guest tortoises show their excitement?

They wee all over the lovely little set we’ve made for them. Rock and roll.

Gail, ever the professional, pretends not to notice as she carries on. These are hingeback tortoises, so-called because they have a hinge in their shell. Why aren’t all animal names that obvious?

Also putting in a guest appearance: this tortoise egg. Yes, that tortoise eggs really are that large. Surprisingly, the baby tortoise inside isn’t yet male or female.

(incidentally, did you notice that somebody had mopped up the tortoise wee in this shot?)

Anyway, what sex the tortoise becomes depends on the temperature at which the egg is incubated. For hingeback tortoises, above 30C leads to a male tortoise, and below 27C leads to a female. Between 27 and 30C… could go either way.

To make it even more confusing – for different species of tortoise, it might be the other way around. Keeping up at the back, there? Good.

Altogether now…. aaaaaahhhh! These are very young tortoises, bred in captivity of course because it’s now illegal to move tortoises between countries. Anyway – back to the How. At this age, it turns out to be extremely hard to tell if the tortoises are male or female.

Because the way you can tell is from the length of the tortoise’s tale.

A large tale like this is a sure sign of a male tortoise…

…while a short tale like this is a female tortoise. Don’t be fooled by the female tortoises often being larger than the males – it’s the tale length that’ll tell you.

So, how much of a tell-tale is a tortoise? When it comes to telling what sex they are, their tails can’t keep a secret at all.