What kind of glue to use

What kind of glue is safe to use when trying to adhere items together (like making hides, gluing rocks together, etc) that will go in a reptiles cage?

Is aquarium sealant safe and strong enough? Epoxy? Cement glue? ?????

Thanks!

I have used this in aquariums before and it works good
http://www.aquatichouse.com/Maintenance_files/Epoxy.asp