American Sycamore needs saving?

Question

I live outside Kansas City with a back yard facing south in direct sun. Planted an eight foot Sycamore tree 3 years ago and everything has been going fine. About a week ago some leaves started yellowing. I started watering a little more than what normally hits the lawn. Today found thousands of household ants at the base of the trunk and about 50% of the leaves have fallen off or are brown. There is also several areas on branches where it looks like the bark split and little wooden spikes started growing out. No idea what is going on, any advice will be appreciated. I assume I need to take pictures and bring them to a tree specialist, just won't have time until next weekend. Thank you,

Answer 1

I love those trees !!!  The ants are probably attacking the roots, Water the h**l out of it by running the hose for 2 days on a low level. Good chance the nest is in the roots somewhere. Sycamores are known for their water tollerance and normally grow quite big next to streams. So the water will have a double effect. Drown the ants and feed the tree! Spray the  tree with a pesticide  will kill the ants and should also keep them from taking refuge in the tree.