Blue Jays are assertive toward other birds and are known for chasing other birds from feeders. Blue Jays are prey to hawks and owls and they will emit an alarm call when these dangers are near. Other smaller birds also recognize this call and will head for cover when they hear it.

Blue Jays are very intelligent birds and also very curious. They often will snatch brightly colored or shiny objects, such as foil or bottle caps. Unlike other colorful birds, Blue Jay feathers do not have a blue pigment, but rather get their blue color from refracted sunlight casting blue light.