This appears to be somewhat of an old wound. Not sure what caused it or how long it has been there but is possibly due to weather related issues or some mechanical damage. The ants are not an issue. I do see callus tissue on one side of one of the wounds which is good, but the wounds are so big it won't likely be able to seal it up. There also appears to be roots growing in one of the wounds; not sure if these are adventisous roots that developed because of the wound or are coming from somewhere else, but I'm guessing they are a result of the stress on the tree.

With all this said, I don't know that there is much you can or need to do other than keep the tree vigorously growing through proper watering, fertilization, and pruning so the tree can continue to seal off the wound. However, it might not hurt to contact a professional arborist, one certified by the ISA to come and do an assesment, they have the skills and training to diagnose the situation. You can find certified arborists in your area by going to this website - https://www.treesaregood.org/.