hitchhicker eel

[Aquaria]

So I was checking out the tank tonight after lights out and decided to check the sump rock tosee if anything interesting popped up as I added some cheato n a light a couple weeks ago and as I'm moving the flashlight around I noticed an eye what I seen was about an inch of a fish or eel and he's about 4mm in diameter. Should I add some mysis to the sump? Maybe cyclopeze since he's so small? I would assume not a lot of food makes it to that end of the sump and would like to see him live. Also are there any bad eel hitchhickers? Is it possible he came with the cheato? It's the only thing I added to the sump in a year