Exhaust and intake pipe question

I’m sorry if this is a dumb question. I just upgraded from an 80% to a 95%. My old furnace went through a chimney and my new furnace goes through PVC piping to the side of my house. The piping is closer to the ground, and I was wondering if I needed to cover it with any type of mesh/wiring? A breathable one obviously, because it can’t be starved for air and the carbon monoxide needs to vent. I’m just worried about small critters going in these tubes, dying, clogging them up, etc? I assume they won’t during the winter because my furnace turns on enough to dissuade them…but in the summer, my furnace will be off from probably May-September/October, so the pipes won’t be used at that point.