Baby Shrimp in Filter

I'm at a loss and hoping someone can help in case I missed something. I have a nicely growing RCS colony, but when I cleaned out my filter a few hours ago, I realized there were a collection not actually in the tank. I pulled 5 young RCS out of the filter box. I have no idea how they got in and would like to not have that happen again.

I have a pre filter sponge on the intake, so I don't see how they could have gotten in that way unless a few eggs were dropped and sucked in then actually managed to hatch. They were in the box part with the media and I would think it would have been hard for them to swim in against the output. I could see maybe one doing that, but five seems unlikely.

They were all alive and seemed to be doing well when I put them in the tank.

 

Shrimp end up in the darndest places. A few in the filter is no bad thing, they feed on the detritus and help keep things tidy. Just be careful when you clean the media. Use a container that you can net any shrimplets out of and returm them to the tank.

 

Well, they all seem to have survived the ordeal. I was concerned I'd come home and see some dead, but they're all having a great evening.

 

I'm not sure how they manage it. I pull one out of my filter every week at water changes. Somehow they're bypassing the pre filter sponge. It was driving me nuts for awhile and I tried several different covers for the filter but still found them in there.
At this point pulling shrimp out of the filter is just part of my weekly maintenance, lol.

 

Lol, good to know, I guess. Silly little things.

 

I find shrimp of all sizes not just the tiny ones in my filters all the time, I've learned to check the buckets before tipping out the water.