rodent trouble

[low_delta]

I've got some sort of rodent living under my garden. It's not eating my plants, so that's good, but it is digging holes looking for food (apparently) and messing up my cacti (getting snagged on the spines?). And it's made a network of burrows, piling the ejected soil all over my plants.

Aside from buying some rat poison, I'm not sure how to get rid of it. What are your suggestions?