Crocodile bulks of swallowed prey flesh and bone. Many large crocodilians swallow stones (called gastroliths or stomach stones), which may act as ballast to balance their bodies or assist in crushing food, similar to grit ingested by birds. Herodotus claimed that Nile crocodiles had a symbiotic relationship with certain birds, such as the Egyptian plover, which enter the crocodile's mouth and pick leeches feeding on the crocodile's blood; with no evidence of this interaction actually occurring in any crocodile species, it is most likely mythical or allegorical fiction. Since they feed by grabbing and holding onto their prey, they have evolved
Mountain plover vegetation short. Plovers like to nest among prairie dog colonies because the foraging and burrowing that these animals do expose even more bare soil which creates an ideal habitat for plover nest sites. It is believed that plovers like to nest on bare soil because they blend into the land hiding them from birds that may prey on them and the short vegetation allows them to easily detect predators on the ground. It is also believed it is easier for them to spot insects to eat. A mountain plover nest has a survival rate that ranges from 26 to 65%.