Keyplus
Only certain tiles are bitumen backed not carpet, strips or otherwise.
If the tiles have been installed properly they will have been laid on an easy-release adhesive or tackifier, so you should easily be able to pull one up.
If they are bitumen backed, just look at the side of the tile, it will look like a thick, solid lump of tar, for want of a better description and if you wipe anything against the side of the tile you will get a sticky, dirty transfer.