You can't, you can only put them outside your door. You actually can. You need to exchange with any person who sells tools that are like traps, but are only allowed inside secret bases.
Put a whole bunch of Rock Traps in front of the entrance.
u can biuld a sercret base anywhere in the underground as long u get a drill from a guy who sale traps
It is someone who sells traps underground.
you click on the trap and press set
You can either buy traps or goods in exchange for spheres. Obviously, you can only do this in the underground
It is a tool you can buy in the Sinnoh Underground from one of the Hiker-vendors (it's random which one sells it). The Sinnoh Underground can be accessed with the Explorer kit. Anyway, what the rock tool does is it puts rock traps in your secret base.
Yes
The Barter exchange are the people in the undergound where you can buy and sell traps and items for your hidden base. pretty cool also if u know where they are.
you can not
Snap traps if they are inside.
go to photobucket and search secret invizimal traps
P-traps and s-traps have odor because of the standing water trapped inside of them. Things like food, sludge, and skin cells coat the inside of the pipes and grow bacteria which produce odor.