 Since common starlings eat insect pests such as <unk> , they are considered beneficial in northern Eurasia , and this was one of the reasons given for introducing the birds elsewhere . Around 25 million nest boxes were erected for this species in the former Soviet Union , and common starlings were found to be effective in controlling the grass <unk> <unk> <unk> in New Zealand . The original Australian introduction was facilitated by the provision of nest boxes to help this mainly insectivorous bird to breed successfully , and even in the US , where this is a pest species , the Department of Agriculture acknowledges that vast numbers of insects are consumed by common starlings . 
