It depends on the size of the area that needs to be treated, and the number of rodents that need to be exterminated. On average, it costs around $200 - $300 for a small home, and around $1,000 or more for a larger business. Rodent extermination generally involves using traps or poison to kill the rodents. Some companies also offer exclusion services to help prevent rodents from entering your home or business in the first place. So if you're seeing evidence of rodent activity (droppings, chewed wires, nests), it's a good idea to call in a professional exterminator right away.