表示成群的蚊子时,可用a swarm of mosquitoes。

knee-high to a mosquito
幼小的孩子a little child
He started reading when he was knee-high to a mosquito.他很小的时候就开始读书。

Mosquitoes carry disease.蚊子会传播疾病。
One type of mosquito can cause malaria.有种蚊子叮人后人会患疟疾。
A swarm of mosquitoes fly into the room.成群的蚊子飞进房间。

［词源］＜西班牙语mosca(苍蝇)