Specialized bat tongue is a hemodynamic nectar mop.

Abstract in brief

• Nectar-feeding bats like Glossophaga soricina use specialized tongues with erectable papillae to effectively collect nectar, functioning much like a brush or mop.
• During feeding, blood flow into the tongue tip causes the papillae to become erect, enabling nectar to be trapped and transported into the mouth by a hydraulic, muscle-driven process.
• The tongue's movement and the erecting papillae are driven by a combination of muscular contraction and blood flow, making it a sophisticated example of a muscular hydrostat system that could inspire the design of tiny, dynamic surgical robots.