Are employees licensee or invitee on employer's premises? I think they are invitee. Although they are on the land for mutual benefit, it does benefit landowner. What do you all think?

well i assume those facts you could argue it that way.  However, en employee could very well be a trespasser (goes there steal records/company property), he could be a fired employee going back to retrieve personal stuff then he would likely not be an invitee.  Depends on the facts.

Er owes Ee higher duty of care
on essay all states have workman' comp law which shelter Er from torts unless criminal or reckless acts by employers
also discuss Learned Hand risk-harm vs. cost to employer
example: should give goggles to protect from eye injury etc
also discuss frolic or detour in light of Respondeat Superior concept