Few years back during spring I noticed soft parts of my deck railing getting chewed up by squirrels. I was puzzled as the squirrels never touched the deck prior

Few years back during spring I noticed soft parts of my deck railing getting chewed up by squirrels. I was puzzled as the squirrels never touched the deck prior to this. I figured the soft wood was weathered as the deck was old and the squirrels were enjoying chewing it or it was a form of oral care. Last spring I had a handyman come by to clean up the yard and paint the fences and told him about the railings. He poked around them and stuck a screwdriver into a soft spot and out came a bunch of carpenter ants. He laughed and said the squirrels weren't ripping up my deck but looking for food. I stupidly assumed squirrels were herbivores when they are in fact omnivorous.