linguistic:paraphrasing, quality:correction
Land clearing

Goats have been used by humans to clear unwanted vegetation for centuries. They have been described as "eating machines" and "biological control agents". There has been a resurgence of this in North America since 1990, when herds were used to clear dry brush from California hillsides thought to be endangered by potential wildfires. This form of using goats to clear land is sometimes known as conservation grazing. Since then, numerous public and private agencies have hired private herds from companies such as Rent A Goat to perform similar tasks. This may be expensive and their smell may be a nuisance. This practice has become popular in the Pacific Northwest, where they are used to remove invasive species not easily removed by humans, including (thorned) blackberry vines and poison oak. Chattanooga, TN and Spartanburg, SC have used goats to control kudzu, an invasive plant species prevalent in the southeastern United States.