Kiddie pool?

I have a digging problem. That's the first step, right? Admit you have a problem? Actually, my dogs have the digging, I have the problem. We've had this problem off and on for a while now with them digging up and killing ALL of the rhodos in the yard, but it hasn't gotten on my nerves until recently. Perhaps the problem has gotten bigger than what I'll allow.

I did some searching online to see if there's any kind of repellent for the areas they're (I say they but I'm not sure whether it's both of them or just one) digging up. No luck. The best I found were websites saying it's either their nature, boredom, or they're trying to find a cool spot in which to lay. Basically, it's the owner's fault.

So what do I do? I go and buy treats/toys to reward(?) their bad behavior. Against my better judgement (because my dogs don't play with dog toys--imagine that!) I bought a rope and a squeaky toy. I hate spending money on stupid things my dogs don't even touch. I also bought 5 big rawhide bones. I'm okay with spending money on these since I know Capone loves them. Athena loves them because Capone loves them. As I gave one to each of them I thought, "Wait. Since Athena's going to run and bury hers...this is just going to make it worse!" AAGH!

This situation has been on my mind all day. Believe it or not this is somewhat of a big deal because I live on a semi-steep hill. Since the dogs (or whichever one it is) are digging right where the hill meets the flat part, I'm afraid there's going to be a major landslide with the first major rain we get. Whether this concern is warranted or not, I don't know. At any rate, if this keeps up I feel like I might have to put in a retaining wall. :oP I would get a landscaper (not sure if this is the correct professional to hire) to come in a take a look at it, but after this kitchen renovation, I HAVE NO MONEY!

At any rate, here's my conclusion: judging from where they're digging (under an azalea, under a mimosa tree, and under the picnic table) I think they're looking for a cool spot to lay in. At the same time, one of them (or both?) are eating the roots of the mimosa. Same thing happened with the rhodos. So are they hungry? Am I not feeding them enough? They're eating grass as well. Or is it the water content in the roots? Does their water get too hot to drink? My boyfriend and I have discussed previously how strange it is that they won't drink the water I provide outside and then when I let them in for the night they'll drink and drink and drink the water that's inside. I even changed the bowl I have for them outside just in case it was the problem.

I considered buying a kiddie pool to put out back, but I did that in NM and they ignored it. Also, since it's hilly back there, the only level place I could put it is on the fire-pit patio and there's not much shade there.

Does anyone have any advice??