Something is digging in my garden?

[slovesn]

Last weekend, we re-landscaped a bed in front of our porch. Ever since the night we finished the project, something has dug a hole in the same exact spot every single night. The hole is in front of one particular bush, but the animal doesn't seem interested in the plant itself...rather the location of the hole. On the surface, there aren't mounds of dirt anywhere, but rather "messed-up" dirt and mulch that the animal presumably kicked back. The entrance of the hole is about 12-14 inches in diameter at its widest part. The hole goes straight down to about 14-16 inches deep, then makes a sharp 90-degree turn. I'm not sure how far the tunnel reaches from there...I'm not about to stick my arm inside just to see how far it will reach!!! But for all I know, the tunnel could go clear out to the street, which is about 100 feet away. Every morning, I refill the hole with dirt and small rocks, and soak it with water, and every night the hole is back again in the same spot. Could there be a nest of babies inside? Why else would the animal return to the exact location, over and over again? I've tried spraying a stinky animal repellant all over the garden, but clearly that did not work. My husband wants to dump rodent poison in the hole, but that's definitely not my preferred method.

So, first question is - any ideas what animal this might be?

Second question is - any suggestions on how to get rid of it? Traps creep me out...because then you have to actually do something with the animal. Poison could be unsafe to pets and children, not to mention the fact that the animal could die in the tunnel! That means that next year when I'm transplanting a bush I could dig up a dead animal. Gross. Oh, and I'm sure the poison get into the soil and harm the surrounding bushes.

Any insight is appreciated. Thank you!