If you can 'catch' and/or kill one, identify it first. If you have an opened bottle of wine, pour a little in a tuna can, or something, and put it UP WIND from the nest. The bees will find it. You don't want to kill them just to kill them. After you catch a couple, there are TONS of sites on the WEB with color pictures of bees to help you identify them.
Many different bees nest in the ground at different times, for different reasons. For example, depending on where you live, you may be looking a BUmblebees which only hibernate in the ground in Winter. When Spring comes, the female leaves the nest, mates w/a drone, and builds her nest ABOVE ground. You may not know this but there is a shortage of pollenating bees these days! They're usually harmless but I can understand your concern. (I'm sure you're not walking in your yard in bare feet!) BUT, at the same time, if you have only one nest, and the bees are 'good bees', maybe marking off the area would bee (no pun intended) in order. (Just a thought.)
Here are a couple links that may be of use to you.
Please consider leaving 'good bees' alone. Again, your best bet is to IDENTIFY what you're dealing with BEFORE you take any mitigation measures. My best to ya and hope this helps.
PS: We have a number of grape-growing vines around out lot. (It use to be part of an apple orchard.) We have bees everywhere! ANd all kinds of bees too but they haven't bothered us for the 6+ years we've been here. We stay away from them. My 4 year old loves watching them 'work'. The more you know about them, the more you know about their 'habits' and, thus, learn to live with them.