Gull spikes have longer wires that pigeon spikes as Gulls have longer legs and can stand astride pigeon spikes. Gulls are also very strong. If they can land nearby and walk up to the spike system, they are capable of ripping them out with their beaks. Therefore the installations need to prevent the birds from landing adjacent to areas being protected. Also AVIFIX adhesive (available in white or grey) should be used to ensure greater adhesion.