I found what appeared to be aphids or scales with the uninvited ladybugs feasting on them on my river birch, only to be chased away by ants tending the larval insects. I know ants/aphids have a symbiotic relationship, but have only encountered this one other time. What was also intriguing was that there were wasps flying near the aphids/scales. Could these be parasitoids? It amazed me how populated the birch tree was. I found many different types of insects on it.

Pictured is an ant tending the larval insects.