Share 'Parasites and other pointless, harmful creatures'

I'm an atheist. So I just thought of a great argument. My dog just had a tick, which as most of you know can cause lime disease. This brought me to the thought of why were they created if they can be such a harmful creature? That then brought me to why were spiders created? To eat the flies and mosquitos and such. Then why were mosquitos and flies created? All they do is cause harm and deaths. So…