I have been trying for about 15 months to ID this bean. If yours are the same as mine, the black sticky substance that looks like ants is the mature epidermis of the pod. The pod when half mature is reddish and smooth, At maturity the pod is red/black and grossly wrinkled. Some believe that the beans cause an allergic reaction in non-asian people. The flowers are either pale lilac or yellow.

I found out the sticky black substances were actually black aphids. It kind of stunt the growth of the plants, but attracted lots of ladybugs. I uprooted the beans since it no longer producing.