Yeah, sounds normal, just like the bathroom window fogging up when you take a shower, warm water evaporates quicker and more volume than cooler water. When the warm moist air hits a cooler surface, the water condenses.
Works great as an indicator your snake dropped a bomb that needs cleaning. 
-----
Thanks,
Dave "Rainbows-R-Us"
0.1 Wife (WC)
0.2 kids (CBB)
4.12 Brazilian Rainbow Boa
2.1 Hypomelanistic BRB
0.1 Het for Hypomelanistic BRB
0.1 BCI "Elvira" normal from 1989
1.0 BCI albino / het-anery
0.1 BCI Hypo / het-albino
0.1 BCI Anery / het-albino
0.1 BCI Hypo (possible super)
1.0 BCI albino het stripe
1.0 BCI salmon hypo
0.1 BCI ghost
lots.lots.lots feeder mice and rats 