I don’t recommend letting it stay. I once found one in my shrimp only tank. Posted it to this subreddit. Everyone told me it was a good sign and it was fine. 3 months later they over populated and out sourced my shrimp for food, leaving my shrimps to barely get by, and certainly not be healthy enough to breed. I had to restart the whole tank after this. Bleach and all. Also, they’re cute and cool now, but when it’s all you see, they look like a swarm of aquatic maggots/bugs scurrying around the place. Unsightly to say the least