Select from options: Continue writing the next sentence.

How to keep birds from nesting 
Use porcupine wire to deter birds from landing on rafters. 
Porcupine wire creates an uneven landing place, which makes any birds nesting there unlikely. Lay out a length of porcupine wire over any rafters where you don't want birds to nest to keep them away.

OPT:
[1]. Make sure your patch is thick enough that birds won't be able to jump onto the rafters. If you don't have porcupine wire, you can make it even more complex by getting a material like cowhide.
[2]. Reach up to the ceiling in one corner of your home and grip it at the narrowest point. To keep your bird off the perch, work wood scraps into the center of the wire, then bury the wire coil into some unrotted wood or another item.
[3]. This works especially well if you have bird-proofed rafters. Avoid using porcupine wire on rafters that are shingled.
[4]. Porcupine wires have heavy prongs that stick out in every direction, and they can be purchased online or at most hardware stores. Lay out bird netting over large areas where you don't want birds to nest.
Answer:
[4].