The term 'ANT OR MOSQUITO' can be summarized by the crossword solution 'PEST, ' which is a four-letter word. Pests are organisms that cause damage to crops, livestock, and other resources. Common examples of pests include ants, mosquitoes, rodents, and insects. These organisms can spread diseases, contaminate food, and cause structural damage to buildings. PEST control is an important part of maintaining a healthy environment.