Those of you that have seen the film "Antz" might remember the cartoon ants drinking "Aphid juice" at their "bar".
Those of you that haven't seen that film will probably know the phenomenon of "Aphid milking" carried out by ants in real life.
Our Potato plants have quite a population of the Black Aphid or BlackFly. We also have a good population of the common Black Ant (the most commonly seen ant species in the UK), which climb up our Potato plants to milk the BlackFly.
The reason behind this is that the aphids produce a sweet honeydew which the ants adore.
Ants can be seen to stroke the aphids, to encourage them to produce this honeydew - in the same way that, for example, a doe will lick around the arsehole of its hind, to encourage it to defaecate.
Some aphids are even carried back to the ants nest, as milky prisoners...
I took a few photos of our ants milking our Blackfly this afternoon - this is the best I'm afraid!