Like a sieve
Flamingos use their bill to filter out microorganisms using their inbuilt water filter. When foraging for food, they pivot their bill back and forth. Then they spit out the water with their tongue. The food stays attached to the fine combs in their bill.
Standing still
Their distinguishing feature is standing on one leg. They have no problem balancing. They have a special leg joint, that they can snap into place. So, Chilean Flamingos can rest and sleep safely on one leg, without it giving way.