This unit is expensive at $578 BUT, it's guaranteed to work. Their normal guarantee is 90 days. I negotiated that out to 6 months. The cycle of the geese in nesting, having babies (goslings, right?), etc. has something to do with the results. So I wanted to make sure we gave it ample time to work and could verify the results. The cage around the unit is supposed to make it vandal and theft proof. The manufacturer told me they've never had one stolen or damaged when using the cage (but that part is not guaranteed). I'm crossing my fingers.
Let me summarize the science behind this as it was explained to me by the company representative. You put the unit in the ground at the height of a goose. It blinks once every two seconds. Geese have eyelids but they are unable to hide their eyes when sleeping. She said they were the only fowl who couldn't tuck their heads under their wings and sleep. So they can't get away from the blinking, they think it could be a predator, and they just avoid the area day or night. She said that if I was sleeping and had my eyes closed but someone was flashing a light in my face every 2 seconds, I would probably leave and go to the other room to sleep. I told her I would and she said "so would the geese and then they just stay away". And since their eyes are much more sensitive, it doesn't take as much of a nuisance light. Good analogy I thought. Worked on me.
Let me tell you why I thought it was worth spending the money on this. It's mostly our little ones that are using the beach. I've gotten MANY comments on how people would use the beach more if the geese droppings weren't there. So I thought it was worth $578 to ensure our young ones didn't have to dig up droppings when building their sand castles. If it works, and does for years, it will be more than worth it. In addition, the money back guarantee will be exercised if it doesn't work. I've got a reminder set up on my calendar for 1 week before the 6 month deadline. If it's not working by then, it's going back.