Hamster Freezing

Question
Hi,
Today when I reached in to pick up my hamster she froze, and didn't move even when I started moving her around and poking her. Ten minutes later she was running about like normal. Could you tell me why?
I'm sure there's nothing wrong with her - but it's better to be safe rather than sorry.
I've just rescued two syrian hamsters - which I've never had before, so I'm a little wary of behaviour etc. I'm also concerned that they might not have had good diet before hand as their cages just seemed to be full of dry white urine caked everywhere and cheerios stashed in the corners. Their urine is very white - is this normal too? Or should I watch out for any other signs of illness.
One is about a year old, and the other (her daughter) is 8 months.
Thank you and Kind Regards,
Helen

Answer
What happened was, your female is in heat. When a female Syrian is in heat (every 4 days or so), some will freeze in place when touched. Nothing is wrong with her, and it's a trait most breeders prefer, since they have a visible cue when to breed her.