I've got problems with birds sitting on some wiring in the rafters on my porch. Is there anything I could smear on the wires to deter them?

The best long term fix is installing Stealth bird netting on the entire underside. The white or transluescent 3/4" would look nice if done with care.

How is that a problem? They'll just find another perch.

It's a problem because there is a table underneath and I'm tired of cleaning it. I dont care if they find someplace else to perch. If the next area becomes a problem, I'll do the same.

Gotcha! Thanks, BB

Do what Bob said, and make sure you do the exterior overhang so they don't end up on top of the net.

I would not net,,,, I would finish it out with wood or vinyl….

Hang a drop ceiling above where you don't want them pooping. Doesn't need to be anything fancy or expensive.

The very best stuff I found is "Bird-X" goo / glue / goop. This is like silicone caulk except it takes years to dry out and remains very, very sticky all that time. It isn't intended to catch the birds but to deter them, and it sure does. Birds which even get a little on their claws find it so annoying that they don't return. You will have the same experience so don't put it anywhere you plan put your hands on again. I only wish I had found this before my years-long effort of trying everything else.

It also picks any and all dust and dirt that comes in contact with it which reduces its adhesive effect.