How can it be protected?

Could you show a picture or two so others see what you see?

If there's rodents in a house they will chew on things. Those who take pride in their home "PROTECT" their home from rodents so aren't faced with chewing problems.

An easy fix is steel wool glued on tot he opening it usually deters them but a pic of your situation is a must for real help.

Why is there insulation on the exterior/ All my insulated ducts are under the house. Anything on the outside, has a metal shield over it.

There is a small part of the duct (about 1` foot) from the compressor going into the wall on the outside. What kind of metal shields are available to protect this.

Your picture needs to be from further back.

Unless you have a packaged system where the air handler, heat and AC are all in one unit outside, what you are probably asking about are the refrigerant lines running from your compressor to your air handler, and not ducting.

Your picture is pretty hard to see. So dont know how yours is set up. It appears to be a diy set up. A professional company would have put the metal shield there. The shield mounts to the back of the unit, and then to the house.

What you are seeing in my picture is the unit on the left, and the top, and down the side. There is a flange on the right hand side of sides and top, that is mounted to the house. Then it is caulked all the way around

Mine is just the conduit too, although it's still insulated. You might need to consult both an HVAC company and an exterminator to see what can be done.

If the gap is small, expanding foam may work. Keeping them out and away from the ducts is the only solution.

Steel wool usually doesn't work to plug cracks preventing rodent passage.

Sktn has the right idea.

klem1 will know.

@PPF. you are right. It is the refrigerant lines (copper pipe with insulation) not ducts.

We had pack rats chewing our air conditioner wires. We wrapped them in metal mesh secured with metal cable ties. It seems to have worked.

Eco friendly rodent control advice.

@Lomo, I have one of those too, but I've never seen one on a coffee maker. I guess it was appealing because it was warm. :-)

DH suggests covering the conduit in PVC or sheet metal. He says the coating on the cables does attract rodents.

I don’t what he used, but my pest control guy “rodent proofed” everything outside my home ( with access ) including our pool filter, etc. Five years , no problems.

BTW, cats work too.