Possible to make enemies path over debris while colonists don't?

[Tinyboss]

My current base is built in a dead-end clearing inside a mountain, only one way in/out. I stacked rubble in that corridor with the goal of slowing down enemies as they enter. But I wanted to allow my colonists to bypass it, so I made another entrance with a steel door.

I was hoping the enemies would still path through the rubble, but instead they just knock down the door. Is there a better way to do this?

[Endoric]

Maybe add a door for them to knock down in the rubble path.

[harpo99999]

perhaps one or more turrets well away from the door (but within the turret's range of the door to shoot the raiders in the back), the raiders usually target turrets then doors

[MikhailBoho]

Do you have a picture of the placement? If they see your entry door first, they'll go for that. The trick is to make walls that route them directly into your killbox.

[TheKanganoid]

you can always build a single block stockpile for stone next to the door and throw a wall up before or after the door.  Then knock it down after the fight.  Bit more micromanagement but works okay.

[milon]

There's a much easier way: You built a separate entrance for you colonists, which is a great start.  But the pirates look at a hallway with 1 door vs a long path over rubble, and they choose the obviously easiest path of hallway with 1 door.  Add more doors!  If you've got 3-8 auto doors in a row, your colonists will path through it just fine.  Raiders, on the other hand, will usually decide it's faster/easier to walk through the rubble. 

[Tinyboss]

Thanks to everyone for the replies! Since Infinifactory just came out I'm  kinda obsessing on that, but when I get back to Rimworld I'll give these ideas a try!