My first thought is that the no pollen hive is being robbed out.
Open it up and see what is going on? If they are queenless they have nothing to defend and will usually be calm.
If you have no brood or just drone they are likely queen less. Multiple eggs in a cell is another vote for queen less.
Maybe they superseded the queen and you are seeing a brood break between queens?
Can you find your queen?
Do you have a resource hive you can rob a frame with fresh eggs in it from? So they can make a new queen if they need one. Don't rob from your best to fix a dud. Don't knock back a strong one for a weak one, is the old school rule. That does not mean you should not replicate a great hive to cover losses though. Depends on what suits your situation.
I would not put a queen in it without looking very hard for an existing queen. If there is an existing queen the bees may not feed or kill a perceived "competitor". Even if the existing queen is not a good queen. I learned this the hard way, they killed 2 queens and would not make a new one with the brood I gave them. You almost have to remove the old queen for ~24hrs to get acceptance for a new queen.
Another clue is a queenless hive has a more intense buzzz, i think they are fanning looking to pick up a queen phermone.
Early on in the queenless process they will often fill the hive with nectar leaving not enough room for a queen to lay (honey bound). Once they have been queenless for long enough the other bees will start to rob.
Even if you loose them all is not lost, you have the drawn comb you can give to your strong ones and make them grow faster. The queen can lay faster than they can build comb. So adding drawn comb to the brood area will get laid up as soon as it is cleaned. For instance I have an early boomer in a single deep and a medium showing 7 frames of bees in the medium already. I added a box of drawn comb with 2 frames of honey on the outsides UNDER the deep brood box to free them up and prime them for a april split. Another colony in the same configuration was bearding today I will take another box from my dead ones to boost that one as well.
I have the feeling this year is going to be a really good year barring any major storms that mess with pollination. I am seeing mature drone pupas so they will be able to make queens in a few weeks. April is going to be swarm city!