Traditionally blood for film is corn syrup and food coloring. When "Conan the Barbarian" was being filmed they had to mix vodka in the mix to keep the cornsyrup from freezing during the winter fight scenes. Several members of the crew were caught with red tongues when a gallon of the blood went missing.
Well we have a different problem all together. We have continuous rain. We will need to devise a 'blood' that will flow smoothly and mix with the rain while not staining the clothing as paint or food coloring would. Starting Monday the 19th we are doing "BLOOD TESTS". We'll post the results.