The Tiny Vampire From Outer Space That's Bitey IV Vampires on Earth

Shadow, Marcus and their friends made it to Earth, but they still have a food problem. Earthling blood isn't palatable, and they only have a two-month supply of bloodbags. Marcus must find a way to distill Earthling blood and create a long-term food supply that will feed them and their growing vampire families while not alerting the humans to their presence.