My Chickens are Sneezing Why?

[Dark4]

I have 5 five week old bearded silkie bantams, and they've been sneezing sense they hatched. Thay live in a 20 gallon tank with a heat lamp so there warm and don't get drafts but it is kind of dusty in there cage, so I'm just wondering if there's anything I should do or if it's ok for them to be sneezing sometimes without any other sines of sickness.
Thank You

 

[Dar]

it could be the dust from the bedding..

what kind of bedding are you using?

I would move them to a cage where there is more ventilation.. if they get over heated it could spell disaster.. also a tank gets much hotter then we think.. make sure the tank is out of direct sun light.

A rubbermaid container thats larger then the tank would be good too... or go to an appliance store and get a fridge or stove box they make great brooders