vermin

[Ember]

Snakes eat vermin and therefore have a purpose. Apart from those who like to keep rats and mice do they do any good?

[Kit]

I'm not sure that I'd agree that wild animals have a "purpose" - unless they are trained, eg drug sniffer dogs have a purpose, because we use them specifically for the task. Vermin are only vermin when we define them as such - rats and mice, like all other creatures on the planet, are only doing their best to survive, and it's not their fault that this doesn't fit in with us. The good they do is in simply being there and being part of Earth's biodiversity. And being food for snakes.

[football]

Owls eat rats & mice, its no good eradicating one species because we need biodiversity. Animals, including insects are needed. Once there is extinction its (too late) no good to say the dodo would have been useful to the starving millions. The dodo would have been easier to keep than chickens.

[football]

As above the same is true about plant species. The plant is a weed if its invasive or it wasn't put there & its in the wrong place. Animals are only a nuisance if they swarm or are dangerous to humans.