Short Final: Glider Refueling

My home airport often has gliders operating north of the field, which led to the following exchange:

Cessna C-FABC: Pitt Tower, C-FABC ready for takeoff 26L, northbound departure. I guess I'll have to fly west for a while for the gliders?

Tower: Negative, I can clear you direct north; the gliders are down for refueling.

Unknown voice: What do they do, put more air in them?

Charlie Gibbs