According to the results of professional surveys, the sticker silhouettes of birds of prey that used to be placed on glass surfaces as a warning for small flying birds, do not work. I tried to come up with something that the birds could accept as an adequate predator and thus be saved from crashing into glass surfaces. Funnily enough, in one of the places, namely on the shop window near the entrance to the cableway to Petřín, where I applied the sticker silhouettes of the bird and the hunter, they decided to keep the bird only, not the shooter.