So here is some nectar from my film.

So here is some nectar from my film.

And here is the long probosced fly that has not gotten any nectar from the mimic, because the mimic doesn't give it any nectar. It thought it would get some.

And when it takes the nectar, the flowers don't feel shortchanged.

They drink this fabulous nectar and then they're all a bit sticky.

And basically what the insect has to do we're in the middle of the flower it has to stick its little proboscis right into the middle of that and all the way down that nectar tube to get to the nectar.

They might say, I've got a bit of nectar. Do you want to come and get it?

What the honey bee does it pollinates, takes nectar from the flower, pollinates another flower, cross pollinates.

They get paid by pollen and nectar, to move that male sperm, the pollen, from flower to flower.

There's a symbiotic relationship there, whether it's flies or birds or bees, they're getting something in return, and that something in return is generally nectar.

This is a plant here that insects in South Africa just love, and they've evolved with a long proboscis to get the nectar at the bottom.

And the bee has been cleverly fooled into taking the nectar, and also picking up some powder on its leg, and going off to the next blossom.

But some plants are manipulating animals, like in the case of orchids that promise sex and nectar and give in change nothing for the transportation of the pollen.

Mosquitoes actually live ... their day to day nutrition comes from nectar, from flowers in fact, in the lab, we feed ours raisins but the female needs the blood meal.

And that bee, no doubt, assumed that it had decided, I'm going for that apple tree, I'm going for that blossom, I'm going to get the nectar and I'm going to leave.

Now you can imagine that if nectar is such a valuable thing and expensive for the plant to produce and it attracts lots of pollinators, then, just as in human sex, people might start to deceive.

This orchid, known as Darwin's orchid, because it's one that he studied and made a wonderful prediction when he saw it you can see that there's a very long nectar tube that descends down from the orchid.

So not only has the fly not got the nectar from the mimic plant, it's also if you look very closely just at the head end, you can see that it's got a bit of pollen that it would be transmitting to another plant, if only some botanist hadn't come along and stuck it to a blue piece of card.