Is my Dwarf Hamster safe from falling from tubes?

[cypher]

If you use food bowls then yes you should always have two, they can still squabble over the bowls with two though so it's best to scatter feed with a pair, just scatter the food around the cage.
Squabbling a bit then sleeping together is normal, one will always be dominant in any pair so you need to keep a close watch on them all the time as it can escalate quickly into fighting, if that does happen they need to be separated into their own permanent cages or bins.

[Pebbles82]

Excellent you found a good bin Give them a week or so to settle in. Maybe you could make a temporary lid out of just mesh and a couple of pegs to clip it to the sides (although making sure there are no sharp edges) until they're settled and you can make a full lid. You could probably get away with not cutting the sides of the bin if the whole lid was a mesh lid. I've also seen this idea for a ventilated top lid using baking grids

(First two photos on here)

https://www.google.co.uk/search?q=ir...w=1366&bih=603

[cypher]

The baking grid idea is fine if you can find some that aren't coated, just plain metal as some of the coating they often have can be dangerous if they did manage to get to it.