Flue slope. Question-I've seen this type of venting 3-4 times a month in older houses and never had anyone complain. The bottom metal flue is the 80% furnace with an uphill rise from it to the newly lined masonry chimney (stainless steel liner).
Monarch butterflies utilize different habitat in the warm months versus the cold months. In the spring, summer and early fall, they can be found wherever there are milkweeds. Monarchs lay their eggs on milkweeds and they're always searching for them in fields, meadows and parks.
At night or during inclement weather, most butterflies perch on the underside of a leaf, crawl deep between blades of grass or into a crevice in rocks, or find so me other shelter then sleep. You can provide a Butterfly House for butterflies, but it is not know if they actually utilize these abodes.