"You have to ingest that stuff; not just sleep in a room where they're potted," he complained.
fusca show that the insect is able to ingest considerably more than (sometimes more than twice) its own weight of blood, which would appear to be the only food, and must be drawn from the tissues of a victim.
They ingest the mucus and, to some extent, the blood of their host by the aid of a sucking pharynx through which the food passes into the bifurcated alimentary sac and its branched caeca.
For example, a person suffering from a cold may ingest an herbal substance that mimics the symptoms of the cold, although the substance will typically be greatly diluted.
The former "piggy backs" on fat when entering the body, making it a requirement to consume proper amounts of fat for complete absorption, and it also makes it hard to get rid of in case you accidentally ingest too much.