Broad beans and ants

My broad beans are growing briliantly, with the first couple of pods now showing.  Last week I noticed that they were crawling with ants so I pinched out the top shoot incase there were blackfly (?) about.  Unfortunately, looked today and can still see quite a few ants.  Can't see the blackfly though.  Help?  What shall I do, or are the ants just looking for something that isn't there?

i had a few ants on mine ,which were planted in nov,,they dont seem to be doing any harm,no sign of black fly thou

looked today had black fly,,i think the ants are on their to eat the black fly??
picked off the tips and brought them home,washed the blackfly off,and the odd ant ,put them in fridge for later,,,,broad bean tips not the ants ants and blackfly,,hehee

Hi
 read about picking out the top of broad beans but when do I do it? Is it only if you get the black fly? Shall have to remember the one about jam as we have lots of ants in the compost bin
 
Thanx