Sentence:  [T]he Employments of the common Ants or Workers [...] are partly the Management of the Young, and the Building their little Hills of Straw, <WSD>Rubbiſh</WSD>, and Particles of Earth, mixed with Blades of Graſs, into little Mounds or Ramparts, on which to expoſe the Eggs and Nymphs to the Sun-beams; their other great Employment is, in collecting Proviſions. 
Meaning of the word marked with <WSD> tags:  Garbage, junk, refuse, trash, waste.