This idea came to me after a day of fishing (I lost my best lure, but through the miracle of snorkeling, found it.) This seems like a simple idea, and I'm surprised it hasn't been invented yet. It is an improvement on the lures that supposedly look like a wounded fish.

The idea is simple. A small, sealable "refill tube" connects to a hollow area inside the lure. This is the reservoir for fish blood. A thin membrane on one side of the lure allows the blood to seep out. You refill by filling an eyedropper with blood and inserting it into the refill tube. _{(I'm being brief right now because this is the third time I've typed this and I'm getting tired.)}