 They gather up by the millions. That's how they travel back in a mass. And it looks like, on the radar doppler, a storm. The Purple Martins know where they spent the summer and will return there again the next year. They've been here before. This is not our earliest, but this year Brian got his on the 6th of March. I got mine on the 9th. Their life expectancy is five to seven years. And without housing, such as Brian and Ben provide here in Griggsville, they could go extinct.