With every action - (spraying poison to rid of one species) - their is an
opposite reaction.
In this case - many other living organisms that are not the target species.
Plus - the residual poison in and on the intended species, can kill many of the
species that were not intended to be killed.
EX: Over the many years of helping the Bluebirds here in my area to prosper
through placement of breeding boxes, I saw several examples where the use of
common household herbicides and insecticides eventually killed the young being
fed from the still live poisoned insects before they died. I estimated over 20
plus years, over 12 broods at 4 birds each average, died because of the use of
common accepted household poisons.
When you target a species for killing through spraying, many other species get
killed as well, plus the balance of that ecosystem will be disrupted as well -
some for many years to come...
Paul Carrier