****.
Move quickly. Clean out everything and wipe it down. Is the bird seed anywhere near other food? Examine everything extremely carefully – each fold of packaging. You're looking for the weevils but also anything that looks like spiders' webs. You need to wipe down every surface of every can, tin, package etc. They'll eat anything with grains and can get in plastic containers and will hide in the thread of glass jar lids etc – it's unreal. If in doubt – dump it. You only need to miss one and they're there forever.
Don't dump it on the lawn – the little bastards can crawl bloody quickly. Bag it twice and dump it somewhere far from your house.