yes, they can. But they have no reason to do so unless that is where their foos is. Mosquitoes usually fly at heights of about 25 feet above the ground. But they have also been found in tree holes of over 40 foot in height and have been found breeding at altitudes of up to 8,000 feet in the Himalayas. They have even been found in jet streams that are an incredible 33,000-52,000 feet above ground. However , studies showed they were aided by the wind to het that high.