Why did God create pests such as mosquitoes and flies?

In the beginning all was good (Ge 1:31). The bugs stayed on the trees an didn't bother anyone. Sin changed all of that (Ge 3:17) [example: "Help mum, the bear is eating me": Teen's desperate...call: A distraught mother listened on a mobile phone as her teenage daughter was eaten alive by a brown bear and its three cubs] Ro 8:22

Life - If we understood everything we would not draw near to
him (Rogers). Ro 8: 20-21, Eccl 3:11.

It's time for you to get a life (right click, 'save target as' to download) by Adrian Rogers

Why did God create pests such as mosquitoes and flies?