... hhhmmm ... many, many years ago, possibly even before you were born, I have watched a documentary featuring Lemming mass suicide, guess what, that's a myth too.
If something or even somebody is a pest lies in the eye of the beholder. And think about it, there is now only about 1% of the African Elephant population there was before the 1990s. In about 100 years 99% of the population has been killed by man - mostly for two big teeth. So who is the greater pest?
How much of a pest could they be now if there once were about 100 times more animals and there were still plants and other things left on the continent.
Wolfs in Europe, Bears in Europe, Vultures in Europe, Lynx in Europe ... Elephants in Africa and Asia ... Sharks, Tuna, Whales ...
Of course, they have all been a pest, but man is not, because he is the pride/summit of creation.
You know there is possibly only one creature on this planet that has killed more other living creatures on this planet than man himself - but maybe it is even not a creature, because scientific community still discusses if they are alive. By the way it is not a single species, but a whole class: viruses!