Cuyaba Dwarf Frog

Image: Felipe Gomes
Eupemphix nattereri

It's a frog with eyes in the back of his... end.

Not REAL eyes, of course. That would make him an alien, and the invasion isn't scheduled for at least another 6 months. Rather they're two, great big blobs that look just like menacing black eyes. Watching. Watching. Watchfully watching watchers. Except they're not REALLY eyes so they're not watching anything. Unless... are eyes in the eye of the beholder?

Image: Lucas Grandinetti

Cuyaba Dwarf Frogs are indeed rather dwarfish. Females don't reach much more than 5 cm (2 in) long, and males are ever so slightly smaller.

They live in open savannah and grasslands in Brazil, shunning the famous rainforests for a somewhat drier, less tree-riddled habitat.

Video: Joe Furman

When predators come calling, butt cheeks get sprawling. The frog turns around and puffs himself up to his mightiest girth so that his eye spots bulge out of his new, rear-facing face. None can survive the awful gaze of those terrible eyes. Or at the very least no-one's winning in a stare-out contest.

With that unpleasantness over, the male can at last inflate a completely different part of his body...

Image: Luciano Leone

His vocal sac! Of course.

The rainy season comes along and now Cuyaba Dwarf Frogs can make use of all that flood water. Males call out to the females and the females are interested. You might even say they make eyes at him.

Image: Ariovaldo Giaretta

Thing is, Cubaya Dwarf Frogs belong to a larger group known as Foam Frogs. They get their name from the weird foam nests they produce from a kind of secretion. Usually each couple tries to make a nice, private nest for themselves but sometimes there are so many couples in close proximity that they all end up in a giant, sexy bubble bath.

It's a very healthy bubble bath, though! Full of anti-microbial doodads and high in fibre. OK, not so much fibre, but it's a great place for frog eggs to develop, safe from predators, fungus, bacteria and anything else that might care to munch on a soft, defenceless egg.

Image: Ariovaldo Giaretta

Eventually the foam nests start to break down and the tadpoles are able to escape into the ponds to eat and grow and grow and eat.

I hope they behave themselves. It's almost as their parents have eyes in the back of their heads!