hammie update: 

last night i went to zuzu's and petri's cage to feed them each a kix and noticed that there was a pretty huge blood droplet (relative to hammie size) on the wood plank that has their wheels hammered on it ... then i saw that one of the wheels (they have two - so they can run in tandem) had tiny drops of blood inside like one of them was bleeding and then ran in the wheel ... it was just a smattering of blood evenly all in the wheel. 

zuzu was eating in her food bowl and the other behbeh was sleeping (like usual) in the cushy cabin. i called the pet whisperer and she said that i should move the cabin to see petri and see if she was hurt. i looked at both of them and they looked fine ... the question remains, which one was bleeding and why was she bleeding?