the price has to be high enough
at $10 a rate maybe?
The cost SAVINGS from eliminating desease and destruction would be worth it
FREE rat poison provided, free cages... I dunno
Set free enterprise loose and you will sovle the problem
As I said before, this is a highly urban area, not like some cornfield out in the middle of Podunk. You can't encourage kids to use BB guns to kill the rats because they don't have BB guns, they have real ones--this neighborhood is a Hispanic gang location. The entire park is a tiny speck of green. A bullet's trajectory would probably exceed the length of this park. You certainly don't want people taking potshots at rats and missing, hitting someone's kid or ricocheting off one of the nearby steel supportive posts for the elevated subway line adjacent to the park.
Eliminate the garbage tossed into the street, the nearby overflowing dumpsters and trash receptacles and the rats go elsewhere.