Bees under screen

I had the same thing happen when I put my nucs into the hives. The straglers and flighty ones over the next few days ended up on the SBB. I sugar sprayed them and brushed them off and installed the check board. They found a hole and squeezed in again. The next day I broke out the bee vac I made out of a cooler and sucked them all up as a dry run for the vac. Worked really well. I removed the outer and inner cover and sprayed them again and dumped them in. All but two or three stayed inside.

They smell the hive through the screen and are not smart enough to find the enterance on their own.

If they're trapped in there pull the slide out. If just there because they're bees and do stupid things just leave them alone. They'll find their way to the entrance.