"Throughout the day, agents wearing protective gear worked in the building, at one point carrying out a plastic tub containing three or four rodents."
Coal miners used parakeets in the mines - the birds would die first if there was toxic gas. Maybe they were using the hamsters like that? There were a lot of toxic chemicals there.
"Throughout the day, agents wearing protective gear worked in the building, at one point carrying out a plastic tub containing three or four rodents."
With brown rings on the necks?