Ants and aphids

The outside of the house was painted today;  well rather it was finished off as one side was done a few weeks ago.  Looking very clean and sparkling now...
Whilst clearing up I saw the crocosmia/montbretia flowers had aphids on them and the ants were there too, 'milking' them.  A symbiotic relationship that works well.  I've left them to it - for now!