New Roborovskis sleep in tunnel/tubes and not house.

[Alyrium465]

I recently got 2 young male roborovski hamsters, I set up the cage and put them both in, eventually they both came out of the box and ran about. A few hours later I attached the tube to the cage, it runs from one end of the cage, outside and back in at the other end.

At first they didn't really care, but eventually one explored inside and ever since they have both spent most of there time in it, sleeping there as well.
They even take the bedding from the house that came with the cage, and put it in the tube.

Is this normal behaviour, they still come out to eat and use the wheel, but should I be worried that they are too scared to leave or should I expect this early on?

[cypher]

It is normal for hams to do this with tubes but it's not a good idea!
Often they will sleep, eat & pee in the tubes which quickly becomes very unhealthy.
It can be difficult & stressful to get them out of the tubes too if you need to clean or want to interact with them.
The best option is to remove the tube again, they may be a little upset at first but should soon find a better place to sleep.
Having a tube with a pair could also encourage them to become territorial & fight too so they would do much better without it.

[freyashamsters]

With pairs a confined space to sleep in is definitely a no-no and even if they choose to sleep in something like a tube it should be discouraged.

Maybe take the tube out and replace it with another toy (one that they can't sleep in!) until they get back into sleeping in the hideaway. If when then tube is replaced they start sleeping in that again it will probably have to stay out of the cage for good