Mound made by social insects (3,4)
I believe the answer is:
ant hill
(Other definitions for ant hill that I've seen before include "Home for social workers?" , "Queen's building" , "colony of insects" , "Social insect nest" , "bustling place" .)
I believe the answer is:
ant hill
(Other definitions for ant hill that I've seen before include "Home for social workers?" , "Queen's building" , "colony of insects" , "Social insect nest" , "bustling place" .)