Exposure to air is not the problem. The microbes in the guts will become active as soon as a rodent is thawed out. That is why people gut their kills right away when they hunt or fish to prevent the meat from becoming tainted. Snakes are adapted to eating the gut contents of their food, but only verry fresh as when they kill it themselves.
If the rodents stayed at neer freezing temps the rodents may be OK, but should be tested before beeing given to any snakes. Thaw one as you normally would and cut it open. If it smells or looks at all rotten then toss the lot.
You don't want to take any risks with your snakes. Go with the old saynig for people food, "when in doubt, throw it out".
-----
1.0 BP Nicodemus
0.4 Cal Kings 3 alb 1 het Dora Queen Ace Pearl
2.0 Alb Corn Bizaar Elixir
0.0.1 Rev Alb Nelsons Oden?