I have had neo shrimp in all my tanks and eventually decided to catch as many as I can out of the bigger ones so I can dabble in cichlids. Many weeks/months went by, many cichlids and rainbow fish later. I figured all the shrimp I missed would have been completely wiped out. Wasn't until I had an unrelated reason to turn the lights on in the room the tanks were in and I was super impressed at the amount of shrimp hanging out on top of my lotus leaves and all amongst the many stem plants. Apparently the shrimp I couldn't find have been secretly thriving at night despite some rather aggressive shrimp eaters! I had never seen a single one during the day in all the weeks since I thought I had gotten enough out that no colony would rebuild but they are very easy to find out and about at night. Nature found a way!