Why do these mosquitoes keep perching on the nostrils of frogs who want to eat them?

Biologist John Gould had been snapping pictures of mosquitoes on frogs for years before he noticed a trend — the bloodsuckers always seem to land right on the amphibians' noses.

Why do these mosquitoes keep perching on the nostrils of frogs who want to eat them?
A mosquito perches on the nose of a green and yellow frog perched on a branch.

Biologist John Gould had been snapping pictures of mosquitoes on frogs for years before he noticed a trend — the bloodsuckers always seem to land right on the amphibians' noses.