Shielding ultracold molecules Ultracold molecules hold promise for a wide range of exciting applications. However, such applications are currently hampered by the limited number of ultracold molecular ensembles that can be created and by their short lifetimes. Anderegg et al . used a microwave dressing field to tune the collisional properties of calcium monofluoride molecules trapped in optical tweezers. This approach allowed a sixfold suppression of inelastic trap-loss collisions. This scheme paves the way for the creation of a variety of long-lived ultracold molecular ensembles. —YS