Even on a frigid snowy January morning, the Big Top is the easiest seed feeder to fill. Just lift the bowl off the big hook under the dome. It literally takes less than ten seconds to refill a Big Top. And the dome adjusts up and down on the hanger so larger birds can be excluded. Only clinging birds with strong feet can use the Big Top. And while it may not be squirrel proof, it’s pretty darn squirrel resistant.