Help with a 4e druid

So I'm running an updated keep on Shadowfel game for a group of folks who are new to D&D. The druid constantly wants to shapeshift into a small innocuous animal like a rat or a mouse so she can go and scout out in advance for the party. I can't seem to find any powers that let her do this and I don't want to keep saying no to her requests.

I was toying with the idea that she could change to a small animal but her HP would be reduced to 1 and she would grant CA to any attacks she might take, but she'd be tiny in size and get a +5 bonus to stealth checks.

Any thoughts?