Corrected sentence: The size and shape of a bird's bill can tell us what the bird eats. Falcons catch their prey in the air, and hoopoes use long bills to dig for worms.
Why I changed it:
- "what it eats" was unclear — "it" could sound like the bill eats. I changed it to "what the bird eats" so we know the bird is the one that eats.
- I used "catch" instead of "grab" for falcons because both are okay, but "catch their prey" is a common way to say it. "Prey" means the animals the falcons eat (like other birds or insects).
- I changed "have long bills for digging worms" to "use long bills to dig for worms" because it sounds clearer. The bird uses its bill to dig for worms in the ground.
If you want it even shorter you can say: "A bird's bill shape shows what it eats. Falcons catch food in the air, and hoopoes use long bills to dig for worms."