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Pitcher rims are notoriously slick—many comprise a layer of wax crystals resembling “the slippery coating of a Teflon plan,” while others have “wettable” surfaces that cause insects to slide straight into the pitcher cup, similar to how cars skid across a wet road, says Ulrike Bauer, a researcher at the University of Exeter in England, who studies the mechanics of plant movement.

The regions exposed to the UV became highly “wettable,” meaning water touching those regions spread out immediately rather than bouncing back up.

The team created several designs of the wettable regions, including one with spiral arms radiating out from a center, much like a pinwheel.

As the droplet bounds up from the patterned surface, the portions encountering the wettable spirals stick to the surface, whereas the parts of the droplet in contact with the water-repelling surface rebound immediately.

Depending on the design of the wettable and nonwettable regions, not only can drops be made to rotate, but can also roll, deflect, or show a combination of different motions, making droplets dance to the tune of the surface patterns.