Copepods, Amphipods and well all the pods as far as that goes.....................
If you have Pods and no Pod Hotel, that means they are homeless. That makes you a mean uncaring host. Don't be a jerk, give them a high rise to live in like the Jeffersons.
Pods are an important part of your clean up crew, not just food for fish and corals. Pods take detritus deep inside your live rock where it breaks down closer to anaerobic zones where bacteria that process nitrate live. Show me a tank with a ton of pods and I will show you low nitrates. They are the unsung hero of your clean up crew!
If you have detritus and other goodies in your sump, why would pods make the treacherous journey through the bubble trap, sponge and finally return pump? Not to mention possibly a skimmer or UV. Nope, they are going to stay put, except for the occasional oddball Lewis and Clark type. Certainly not enough to maintain a display tank over time, especially if you have Mandarins or Wrasses.
Addon note: Things like pod hotels and even bristleworm traps need to be seasoned to work properly. Basically, think of it like this, when something is brand new in your tank, most critters are scared of it or literally ignore because it smells or taste weird to them. Allow your new pod hotel or bristleworm trap to sit in your sump or behind your rock pile for 2-3 weeks before actually using it for its intended purpose. Its creates a thin film on all surfaces which are more inviting to the proposed critters. Basically, you need to let a biofilm grow over the surfaces. Ive seen so many comments and articles where someone bought a similar item, threw it in the tank that day, next day they are complaining that it's not working.
Season those new items, no one likes things plain.
Enter the scene......tadaaaaa POD HOTEL
get yours today at https://www.aquariumtanktools.com/product-page/pod-hotel