On Monday's episode Mr Fry mentions that there is "virtually no difference" between frogs and toads. This is incorrect because as far as I know they have different eyes. Toads have slitted reptile eyes and frogs have round pupils.
An Elf Replies...
While I'm sure that your technique is a good rule of thumb for distinguishing between frogs and toads (especially in the UK) there are still exceptions to this rule. For example, check out this Grey Tree Frog whose eyes are slit and this spadefoot toad with round pupils.
There's no strict difference between frogs and toads - toads are a subset of frogs. Generally speaking, toads crawl instead of hopping, have rough skin, are fat-bodied, and live drier lives than frogs. Most frogs have teeth; most toads don't.
As far as the eyes of these animals is concerned: they certainly are quite interesting. All toads and frogs blink when they swallow. This pushes the eye right up against the roof of the mouth, which helps force the food down the throat.
Toads' poisons come from glands behind their eyes (and in some species skin warts.) Some toads can squirt poison from behind their eyes. We're also told that some frogs have a non-lethal mutation that means their eyes develop on the inside of their heads, so they have to open their mouths to see.
So there you have it, we stand by the fact that toads and frogs are virtually indistinguishable. You might be interested that the same is true of moths and butterflies and of doves and pigeons.
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