'birdbrain' is slang for someone who is stupid, someone who has a small brain, especially someone who flies around in a panic instead of stopping to think.
Example: "I took the train, but those birdbrains lost my luggage."
This blog is mainly to explain a different English language expression every day. Sometimes I post other stuff. I also have a YouTube channel which is mostly about computer software: https://www.youtube.com/englishspacedog
