Let's ignore the fact that the sheer number of rabbits is in the millions or that they are everywhere, including the bush where you can't see them, but let's concentrate on the fact that shooting guns in built-up or populated areas is illegal for the obvious reason that it's DANGEROUS and even if you could, that it would take days to hunt all 75 rabbits just on your property as you continually wait for them to come out, or, by the time you cleared the property and moved on to the next, the rabbits next door move in to greener pastures at your place etc etc. Biological warfare is the only way to be sure you get them all.