Tofu pecks

Tofu pecks a lot. Sometimes she'll swallow the rocks she pick off the road, sometimes she'll just keep it in her mouth, moving it back and forth. It's like the sound of eating a hard candy. But eating rocks is no good...this is the second time she has bad, watery poops, and we think its the rocks....what else can it be...just look at the size of the rocks coming out with her watery poop....