Acadian Flycatcher - Empidonax virescens

We've had a little family of these cute birds hanging out in the back fields.
One bird is constantly being followed by three. Hopefully, they're learning to eat deer flies!
While Empidonax species are difficult to distinguish visually, they do have more distinctive calls.
The "peet" call of these birds, plus the fact that I've seen and heard the song calls
earlier this year are a factor in my ID. In any case, they are a very cute little group.