The more than 50,000 species of plants, animals, and microbes introduced into the United States (US) cause more extinction of native species than most any other threat and cause more than 120billionindamagesandcontrolcostseachyear.Inparticular,invasivemammalsandbirdscausemajorenvironmentalandeconomiclossestotalingabout46 billion per year in damage and control costs per year. Feral cats, rats, and hogs are especially serious pests. Pigeons and starlings are a major concern in cities and US agriculture. Prevention and management strategies will be discussed