Try disturbing their nest area and leave maybe a crumpled damp paper towel near their nest. I caught a wild Tapinoma sessile colony with the queen by leaving a small piece of wood lay on my desk. About 24 workers were present underneath it. However, I don't recommend keeping them. As a matter of fsct the 2 species that I am against keeping is T. Sessile and L. Humile. Both are escape artists and for whatever reason they never survive well in captivity. If you don't want a supercolony living in your house attacking all your other ant colonies or making unwanted nests underneath you books or clothes, I would highly suggest some other easier to keep species such as camponotus.
Edited by MegaMyrmex, December 22 2017 - 12:17 PM.
Proverbs 6:6-8 New International Version (NIV)
6 Go to the ant, you sluggard;
consider its ways and be wise!
7 It has no commander,
no overseer or ruler,
8 yet it stores its provisions in summer
and gathers its food at harvest.