Why do blue jays eat my cat food?
Like other Corvids (Jays, Crows, and Ravens), Blue Jays are omnivorous and can eat and digest both animal and plant matter. Animal matter can include insects, carrion, small birds and mammals, and the eggs of other birds. Then there is plant matter including corn, seeds, etc. Your catfood was not only convenient but contains a good source of both animal and plant matter and the opportunistic tendencies of Blue Jays allowed them to take advantage.