yes, nose scarring can be a problem...I have received a couple (most noticeably my ATB) that have bad scarring and partially blocked nostrils from rubbing on screens. But I have also found that if I provide enough hides and appropriate temps, they don't rub their noses! Not a single one of my 13 snakes has ever damaged his/her nose on a screen top (all my cages have screen tops) and the ones with the injuries already have not added to their problems. So my advice is to be aware of this potential problem, but go which ever route you prefer and would be happier with! The main reason I choose screen top is because I use, and only use, heat lamps and florescent lamps (for proper day/night cicle in snake room). I started off with mostly undertank heat pads, but quickly learned that heat lamps are better! Unless you are willing to purchase a thermostat for each cage (can get very expansive) then heat pads get way too hot and can be dangerous..also, they loose their adhesive abilities and fall off. They also do little to nothing to help increase ambient temps. In short, I just try to avoid them all around. I know this is long, but I wanted to explain why I prefer screen tops!
-----
-David
Check out my pet pics at:
http://www.myspace.com/obx_fisherman
1.0 ball python (Pandora - don't ask)
1.0 argentine boa (Prometheus)
0.1 hogg island boa (Andromeda)
0.0.1 brazilian rainbow boa (Inara)
1.0 kenyan sand boa (Diablo)
1.0 normal corn snake(Cypress)
0.1 amery. corn snake (Morgan LaFay)
0.0.1 banded cali. kingsnake (Cain)
1.0 tangerine honduran milksnake (Narcissus)
0.0.1 snow corn snake (Valkyrie)
1.0 amazon tree boa (Pegasus)
0.0.1 colombian boa (Athena)
0.0.1 albino san diego gopher snake (TBD)
0.0.1 sandfish skink (Slick)
0.0.1 fire skink (Phoenix)
1.0 dog (Luke)
the wife's pets:
1.0 bearded dragon (Leonidas)
1.1 ferrets (Ares, Enyo)
0.0.1 betta fish (Captain Morgan)
1.2 cats (Galahad, Ripley and Sassy)