Ant infestation

[Fernando]

From time to time I've ants, too. More or less every summer.
They aren't a problem. Just submerging the pot in a soapy solution (jabón potásico) and giving the ants a way to flee into the garden (a bridge so to say), and they will do so.
You would like it too before repotting! After three years that might be a good thing to do.

In my opinion there is no need to use pesticides.