HUMANE PREVENTION OF PESTS. Jack Pest Deterrent Spikes are an excellent and cost-effective way to deter birds from landing or roosting on your home or property with its stainless steel pointed spikes that act as a barrier. Placed along edges and surfaces where birds like to perch, these humane spike strips prevent pests from causing mess and noise. It's ideal for crows, gulls, pigeons and other large birds but can also deter cats and possums from climbing fences. It's perfect for window sills, roofs and aerials and is flexible to fit curved or flat surfaces. You can easily cut the spike strips to custom length and attach the polycarbonate base strips with screws, nails or glue.