Bird food is three-quarters gone!

[ShazzieB]

3. Yes, most likely squirrels.

Years ago, there was a pair of squirrels that raided my bird feeder constantly. I looked out the window one day and saw one squirrel hanging by his TOES from the line the feeder was hanging from, reaching down to scoop out the seed with his front paws. His partner in crime was on the ground under the feeder, hoovering up all the seeds the first one dropped. (Sadly, I did not get a picture of this. It was back in the days when cameras had to have film in them, and I was caught unprepared.)

Those furry little bandits just about ate me out of house and home. Squirrels are cute little rascals, but they can be hell on bird feeders!