I brought in a small banana tree over winter and later on noticed ants were nesting in it. Since it has warmed up the Banana tree is now outside. I flushed it several times with water and it seemed to have encouraged the ants to move on. Now, they are trying to nest in one of my other houseplants and even some tomato starts I have under lights. I tried flushing them again but I am not sure if it is working. I have also been spraying with soapy water too. Any other methods to get rid of the ants? I worry they will chew on the plant's roots. They also make a mess by pushing soil out of the pots.