Oh that's easy, in Sonic Rush Adventure, all you gotta do is first, find the "Underground Hide-Out" and then... That's it.
Funnily enough they tend to hide underground... if you dig about 12 feet you should find one.
Sonic 's not hiding it because he does not luv her
Yes she is afraid of heights because I heard in Sonic rush adventure that in sky Babylon she tried to hide her fear of heights.
In the underground catacombs.
in the back or underground
To hide from danger.
They hide their treasure underground but they all bury there treasure in different places.
Not if your their going on the underground railroad.
in an underground railroad
yes
To hide from potential predators.
If you mean underground as in sub-terranian, then certainly many hiding places were underground. If you mean underground as in the 'underground railway', a group of people, then yes, some hid as wards of a group.