For a Russian dwarf hamster is a 0.9cm gap in the cage bars OK?

No they shouldn't be able to squeeze through 0.9cm if they're older than 5-6 weeks.

(In response to links posted above)

Please avoid ALL crittertrail/S.A.M cages - they're awful! Tiny, poor ventilation, expensive and break easily.

I'd recommend the Jack 72 if you're in the US.

http://www.rabbitmart.com/shop/index.php?page=shop...

If you're in the UK - I'd recommend the Gabber (criceto) Rex which is a large tank style cage so you don't have to worry about them escaping.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&it...

they could be superb yet in case you imagine they're having a not effortless time attempt putting some fruit tree branches/sticks contained in the tubes that can help them climb. It truly relies upon on the hamster. I easily have 3 and one climbes each thing and something the others dont in any respect.

Hamsters can squueze through very small gaps.

These hamsters may squueze through that.

Allthough it isn't very likely.

If you wanna be really safe buy another cage. sorry.

Otherwise try and keep an eye on them

unfortunately yes, dwarf hamsters can get through o.9mm bars, mine did! thankfully i got him back and bought a new cage. it has a large plastic base and 0.6mm bars.

I don't think so. hamsters can squeeze pretty good and I bet that your hamster is going to escape if you don't get a better cage. I think my suggest below, are going to be good choices

http://www.arcatapet.com/fullsize/8988.jpg

http://www.petsr4u.com/prodimages/superpet/60513.j...

http://www.arcatapet.com/fullsize/8989.jpg

http://im.edirectory.co.uk/p/3140/i/858519.jpg

http://www.bunnybasics.net/images/crittertraily.jp...

If you don't like any of the wire cages, then just choose an aquarium so you don't have to worry about gaps. Good Luck!

They are all very briliant escape artists.

All mine were named after thiefs or escape artists.

Silk, Houdini and Turpin

er no they can squeeze through it