I apologize for this delayed reply to your gardening question. The spring rush has brought a deluge of questions and we are working hard to catch up!
Ants love to nest in places like that. It is not unusual. You can leave them be or if you want treat them with a general purpose insecticide but they are not doing the palm any harm.
Thanks for the question. Best wishes for a wonderful gardening season. Please stop in again soon!
Q&A Library Searching Tips