Birds and Squirrels, What Have They Ever Done For Us?

We had our breakfast in a cafe in a local park this morning and as usual the birds and squirrels were mooching around and my husband watched them and asked 'What do you think they do all day?' and as quick as that my daughter answered 'sit around tweeting' which not only made me laugh but gave me a witty answer to claim as my own if the situation ever crops up again.
To be fair it was quite a sensible question considering it's source and i thought what do they do all day? All i ever see squirrels do is run up and down trees and dig but they can't do that from dusk to dawn every day and the pigeons and seagulls seem to be forever flying around looking for food which has been dropped and then looking for my car and crapping on it's bonnet.
I did notice a few squirrels just sat around on branches doing nothing and some pigeons seemed to be walking around in circles which looked like just for the hell of it and then would fly up on the roof of the hut and just sit there looking around but otherwise my answer to the question of what do they do all day is very little.
A quick Google search showed that Squirrels evolved into the mammals we know today approximately 41.3 million years ago and birds go even further back, 150 million years, while modern humans evolved a relatively short 200,000 years ago and while we have invented motor cars, flight, space travel and agriculture in that time, to my knowledge birds and squirrels have invented nothing and there only contribution to the World has been to warble the occasional song and dig holes in peoples gardens to bury monkey nuts.
All considered, birds and squirrels need to start pulling their weight as i will tell them next week if any of them come sniffing around my egg roll.