If a monster has trip as part of its attack.

[Ozzmal]

Another situation that came up last night. We were fighting some worgs who had trip as part of their attack. Does that mean if we got hit by the worgs that we automatically got tripped? The DM rolled again after we got hit to see if theyre trip attempts were successful. Also, under trip, it sais if you fail a trip attempt by more than 10, that you are tripped instead. Would that be possible in this type of situation? Thanks in advance.

[Lord_Malkov]

Yes the creature has to roll. It gets to attempt a trip maneuver as a free action if the listed attack hits.

And no it does not get tripped in return if it fails by 10. This is an exception that is explicitly listed under the UMR entry for trip.

[Ozzmal]

Thank you very much for the information good sir =)