That is why bird removal schemes, such as trapping or poisoning, are temporary, at best. Habitat modification solves the problem once and for all permanently, which means they don t get to come back over and over again, forever, to kill for profit, at your risk and expense. Harvard University and others have proven that pigeons are as smart as whales, monkeys, or most any other animal on the planet and, in some ways, are even smarter than humans. That goes for other birds, as well. So, unless the phony predators move around like the real thing, they quickly catch on.
Sticky repellents can be very hazardous.
They kill animals by getting into their nose and throat and suffocating them. Or, the goo sticks to feathers or fur causing the poor creature to chill or overheat to death. The messy stuff also damages buildings and is rendered ineffective by dust and debris again, costing more money without solving the problem. Pet food, many plants, and neighbors can attract birds. Also, many harmless and effective anti-roosting products are available to keep birds away.