Maggots of Blow flies are amazing, some animals truly are amazing even though we don't like the idea of maggots creeping around our body, it works. Another fascinating animal most shudder to imagine is the leech.
Leeches are used for very specific applications, particularly in plastic and reconstructive surgery, rather than the historical practice of general bloodletting.
Awesome colour on the flies under direct sunlight, throughout the year I freeze bones in the kitchen to avoid maggots creeping out of the dirtbin.