The phrase "are invaded" is correct and usable in written English.
It can be used in contexts where you are describing an action that is happening to a subject, typically in a passive voice construction.
Example: "The peaceful village is often invaded by tourists during the summer months."
Alternatives: "are overrun" or "are encroached upon".
The aim is to back up the regular army if we are invaded by the Russians.
Legume crowns commonly split under these conditions and are invaded by decay-forming fungi.
All have the sea, of course, but their traditional fishing waters are invaded by the trawlers of industrialized countries.
(But then deceit is an old tradition with us natives. When we are invaded/ colonised/occupied and stripped of all dignity, we turn to guile and opportunism).
At this uniquely dangerous moment, their lives are invaded by Jamie Adam Driverr) and his wife, Darby Amanda Seyfriedd), a dazzlingly seductive twentysomething couple.
Many ecologists have projected that dozens of obscure species of plants and animals are becoming extinct each year as tropical forests are invaded by farmers, loggers and hunters.
There, however, they are invaded by a theatre troupe called the Caveman Group, led by one Masao Anai, who are putting on plays based on Choko's work.
As homages go, this feels both wild and innocent, and some sequences are invaded by bursts of graphics and cartoons — what better image for the restless junior mind?
The bakers' shops are invaded by poor people begging for bread, and the little they obtain costs them double the usual price.
Legume plants, such as peas, beans, and clovers, form "fertilizer nodules" on their roots when they are invaded by rhizobia bacteria.
"Noisy demonstrations are held in the amphitheatre of the body; streets are blocked in the brain by rebels from the cane fields; dreams are invaded by spectral disturbances; affects riot and tear down the work of years".
