A retired engineer from Cedar Rapids who was fed up with wild deer munching on his garden vegetables has invented a product designed to steer away bothersome Bambis. Clay Chalupsky says he tried various concoctions over the years to keep the wandering deer from gobbling up his precious produce. Chalupsky says “In order to teach a dog anything, you have to be smarter than the dog and I thought of that when they ate my tomato plants the first time.” He worked for years to get the right mixture of scents to keep the deer out of his yard and away from his garden. The product Chalupsky developed is called “Deer Fortress” and it’s billed as being a non-toxic, scent-based repellent that stimulates the deer’s flight response. He says it’s odorless to humans and is “the smell of danger to deer.” The hockey-puck sized items sell six for 30-dollars. They went on sale Monday in hardware stores across eastern Iowa and several locations reportedly sold out within minutes. Jan Walsh, who works at a True Value store in Cedar Rapids, was amazed how quickly the product was snapped up. She says everyone has deer problems and they’re willing to try anything to get rid of them.Once they were all gone, Walsh took more than 40 rain checks from customers wanting the product. They’re being made at Goodwill Industries in Cedar Rapids with ingredients from a local feed store. They can also be ordered online at “www.deerfortress.com” and Chalupsky says he got orders Monday from as far away as Massachusetts.