what is the strongest thread that can sew two area rugs together and where can I buy it?

what is the strongest thread that can sew two area rugs together and where can I buy it?
I want to attach two area rugs in my living room together, because they keep moving when my 215 lbs son walks on them.
what thread is the strongest and do they have a matching needle for it?

I tried rug grib and other things, they didn't work, because the area rugs are on the top of the carpet not hard wood.

Also, I've already put heavy furniture on the top of the rugs. still, the parts that is not under the furniture moves a little bit. thanks for any suggestions,.


Answers:

Chosen Answer
HillClimber:  It's called carpet thread and it is available wherever sewing things are sold. You also need a larger needle with a good size eye and a thimble to push it through. Depending on the rug thickness, you may also need a pliers to punch in and pull out.
2010-12-04 09:13:03
paulofhouston:  Wouldn't fishing line work,Say 50 lb test.
2010-12-04 09:21:40