00:00An oxpecker climbs over a massive hippopotamus, searching for unwanted passengers.
00:06Ticks, leeches, and other parasites become an easy meal.
00:11The bird even reaches into the hippo's mouth, removing bits of food and debris.
00:17For the hippo, it's an unusual cleaning service.
00:21But this tiny bird isn't always as helpful as it looks.
