I was having problems with swallows roosting in my carport and pooping on the cars. I couldn't use commercial spikes as they are too high. So I went to my number one design tool, Tinkercad. Knocked up a model and printed some. I installed them with a hot glue gun as I had limited room to use a screwdriver. I printed them on four different printers. A Minda Magician Max, an Anycubic Kobra 2, An Elegoo Neptune 4 and a Flashforge Adventurer 5m. I used Kingroon PLA filament in red grey and black.