I have seen hummingbirds in our yard dart at a spider web and steal the insets from them. This is usually early in the year before the flowers have opened.
There are several websites that can tell you which seed combinations will attract those colorful birds. However...and that's a BIG however, I stopped feeding the birds at the feeders last spring when the local Cooper's hawk decided it was a buffet for him. He would take down the little brown birds right in the yard and tear them up on the lawn. Don't know if your falcon would think the same thing.