Bird spikes are mainly used for bird pest control. Some people have issues that the birds do nesting at their chimneys, rooftops and many other places. To stop birds coming to these places, bird spikes are used. These bird spikes are very much humanely.
It does not harm the bird because the spikes are not sharp. The only purpose is to stop the birds from nesting in the area. It can be installed very easily.
Bird netting does not require any special kind of installation method. One can install it on his own.
Birds spikes main purpose is to stop birds nesting and control pest in certain areas where you may have a problem due to birds. The birds may cause some damage so you install spikes in that area.
Sometimes, bird trapping techniques may be required if birds made a nesting at some place and now that place becomes functional. The birds may get harm of it. For instance, if birds made their nesting at a chimney which was not in function from a long time. Now when it becomes functional, it may cause damage to the birds and the birds may have their chicks in the nests.