Since I'm still having rotten luck getting a competent military going, I always set up a long row of cage traps at the entrance to my forts. Twice now with .25, I've had an unwelcome guest appear at my then-current fort. I've ordered everydwarf into the emergency burrow, and the attackers charge up to my (unlocked and pathable) front entrance and.. just hang around outside. The first was a goblin; the rest of the ambush ran inside and got caught. The second was a minotaur. Is this some new intended behavior? Are they aware the traps are there?
They don't know the exact location of your traps, but they seem to expect them. I don't even have a gate, just a hole in the hillside. They can be tricked to enter, but usually they send only one or two scouts if there is a group. The same with other traps which have some sort of narrow or potentially blocked passage (stairs, doors to tower) and I mean special constructions, not simple weapon or cage traps. I believe it to be intentional, because it is actually a wise move - you are forced to go outside. They go on rampage and kill your animals located outside though. And sometimes they try to go inside, probably led by a fearless leader. Catching the leader may be the reason the are stopped then.
To catch minotaurs, trolls and similar it is best to create bait-traps, with something destructible inside, and relatively far from your fortress. Like this for example:
#######
cc.D.cc
#######
c = cage trap
. = floor
# = wall
D = unlocked door
Such a simple trap is guaranteed to catch minotaurs, cyclops or even dragons, if it is located closer to the edge of the map than any of your more sophisticated traps.