Just read in an old country book on the good against bad in nature.
At one time the Ministry of Agriculture was paying a Shilling(5p)a tail for the grey squirrel.Because a Grey raids the nest of the Wood-pigeon and eats both the eggs and young there was a massive rise in the Woody,and we know what damage they do.
Rooks do a lot of damage to crops but also eat millions of wireworm and leather jackets.
Since birds of prey have been on the protected list there has been a rise in the Bullfinch,a flock of Bullfinches can strip an orchard of the buds of fruit trees.
In any year that there is a shortage of wasps we all say good.But then there is an increase in the larvae of the Cran-fly(leatherjackets)which are no good in anyones garden.One Cran-fly can produce up to 300 of these lavae,the was eats these.
So really there is no winner
I thought it was interesting anyway.