Ant evolution

Come summer, it is the time when we see an army in pursuit.  Pursuit of food, saving up for the rainy day they know surely is to come.  So, it was.  But there was something different with these red ants.  They weren't interested with the flour left on the table after the rotis were made, not the crumbs of sugar. 

They went after something richer.  The empty vessel that contained cheese spread.  And what an army it was - red in colour(the communists would loose) and hundreds of them.  They refused to go away for three days after that.  No amount of sweeping and mopping the home would stop them.  Finally, I had to use Lakshman Rekha. 

I then wondered what they liked.  So, I tried a lot of things.  Bread crumbs left in the waste bin, little bit of wheat flour, little sugar - yet they wouldn't be tempted.  Finally, I thought that they had decided to change the direction of food gathering and hence I was safe.  So, one morning, packing lunch to go to work, I left the pan in which I had sauted the paneer(cottage cheese) on the cooking slab.  When I got back in the evening, the red army was pack in full vigour and then started the routine of trying to discourage them from coming by the usual methods till I hit again on the Lakshman Rekha. 

So, ant colony studies are used so much in computer science.  They go by the source of food as well as the choice of food available.  Okay, this is known.  But is there something called evolution in taste of the ants, that too collective taste ?  Or was it that they had enough of bread crumbs, sugar and wheat flour at home that they had narrowed down their shopping list.  They have left me wondering.