Would it be biologically advantageous for a vampire that doesn't need that much blood to lick away skin in order to extract it, rather than bite?

Question

Let's say that there's a vampire that doesn't need much blood per day - something like a teaspoon. Instead of deriving nutrition from it, they need it for its antibodies, so that their nonfunctional immune system can "adopt" them (long story).

Instead of puncturing the skin and feeding, they use a micro-barbed tongue similar to that of a lion's to scrape the skin off of the area (think minor road rash), followed by lapping up the blood that flows from the abrasion.

Is this a more biologically advantageous method of extracting a small amount of blood from a human body on a regular basis in comparison to a fanged bite?

Advantages I can see:

• it's less likely to result in infection, since the wound isn't as deep, meaning that it's more likely they'll be around for another feeding

• it doesn't require breakable teeth to be inserted into something

• it probably won't be as painful, considering that it doesn't go through as many layers

Answer 1

Your strategy may go through less layers, but it damages more vessels. It will take longer to heal and will expose the victim's body to more germs than if you did a single, small diameter hole.

Your vampire's tongue might be sharp like a lancet instead. Prick a fingertip and suck it. Press it with your lips until fed, then release. The wound will close really quick and will barely leave a mark.