Biologists have uncovered that tiny, finger-like structures called papillae on the suction cups of squid may explain their remarkable ability to stick to surfaces, enabling them to capture prey efficiently. These papillae, found on the edges of the suction cups, appear to help the squid maintain a strong grip on rough or irregular surfaces, which is a different mechanism from what has been observed in other cephalopods like octopuses. This discovery could lead to the development of new materials or adhesion technologies inspired by nature. Cephalopods such as squid and octopuses rely on their arms and tentacles, which are covered in suction cups, to catch and manipulate prey. The surfaces of their prey—like fish, crabs, and shrimp—vary in texture and firmness. For a squid to successfully capture its prey, it must be able to adhere to these surfaces, which can be challenging, especially on rough or uneven textures. If the suction cups are not watertight, liquid can seep in, weakening the grip. The edge of the suction cup must therefore both make contact with the prey and maintain a seal to ensure a strong and stable attachment. In some species, such as the clingfish, suction cups are equipped with soft, flexible structures called micropapillae that mold to the surface they attach to, creating a tight seal. This allows the clingfish to hold on with impressive strength, supporting up to 230 times its body weight. While squid have smaller suction cups, studies suggest they can generate significantly greater suction force than octopuses, though this depends on factors like the size of the suction cup and the area of contact. However, the exact mechanism behind the squid’s suction cups has remained poorly understood, especially compared to other species. A recent study published in the Journal of the Royal Society Interface sheds new light on this mystery. Researchers, led by Brett Klaassen van Oorschot from Wageningen University in the Netherlands, examined the suction cups of the common squid (Sepia officinalis). They found that the papillae on the edge of the suction cups allowed the squid to adhere more effectively to rough or irregular surfaces, such as those of crabs and shrimp. Using a laboratory setup, they tested how well squid suction cups could stick to different surfaces by measuring the force needed to detach a plate from the cups. The results showed that the suction cups adhered best to surfaces that matched the roughness of the papillae—similar to the texture of the squid’s prey. These findings could inspire new technologies, such as grippers for robots or improved medical devices. The researchers are now working on creating bio-inspired suction cups that mimic the squid’s design, aiming to improve our understanding of its biomechanics and develop more effective industrial tools.