Infestation (noun)

1. The presence or establishment of a large number of pests, especially insects, in a place where they are not normally found.
2. The state or condition of being overrun or plagued by pests or unwanted creatures.

Origin:

Late 17th century: from french, from infester, from latin infestare 'attack', from in- 'upon' + festus 'fierce'.

Examples:

1. The infestation of termites caused significant damage to the wooden structures of the building.
2. The infestation of cockroaches was a major health concern and required extermination.
3. The infestation of bedbugs made sleeping in the hotel unbearable.
4. The infestation of ants was controlled by using ant baits.
5. The infestation of rodents caused food contamination and spreading of diseases.