I've noticed that a lot of animal sprays have blood in their brews, will just spreading pure blood around the edges of the garden send animals far away to keep my plants safe?
What about the smell? Will your neighbours put up with that. Besides, blood will eventually turn your garden into a breeding ground for all kinds of bacteria. A simple chicken wire might be a better option but for some reason im sure you've thought of that and have deemed it not fit for the purpose.