Avicides like Avitrol and others called by the vendors "nonviolent" and even "humane" are acutely toxic and cause birds and other animals to suffer immensely.
Some birds gather in large roosts near humans, and because they are perceived as agricultural pests, they are routinely exterminated in large numbers. The destruction of night roosts in addtion to "pests" also kills other birds, whose population is in dangerous decline. This planet is not for humans so exclusively!
Read more: http://www.peta.org/issues/wildlife/cruel-wildlife-control/bird-poisons/#ixzz38G5EA8Dh