" She's easy to use." Laszlo pointed at the doll's neck. "You remove the clamp, insert the small funnel, select two quarts of your favorite blood from Romatech Industries, and fill her up."

I see. Does she light up when she's running low?"

Laszlo frowned. "I suppose I could put in an indicator light- "

― Kerrelyn Sparks , How to Marry a Millionaire Vampire (Love at Stake, #1)