Data from: Behavioral and hormonal responses to urbanization in ants

Urbanization has profound effects on biological communities. Many
organisms cannot persist in anthropogenic environments, while others may
adapt to urban conditions. Behavioral traits can facilitate this
adaptation and predict how species might respond to urbanization. We
studied the behavior of the odorous house ant (Tapinoma sessile) which is
common in both natural (i.e., forests) and urban areas. Relative to
natural environments, colonies in urban areas are typically more
aggressive and have many more workers and queens. To examine how this
variation may influence other behaviors, we compared the exploratory
behavior of T. sessile workers and colonies from natural and urban
environments. We found repeatable variation in exploratory behavior,
suggesting workers have distinct behavioral types. Additionally, colonies
from natural environments had higher exploration and foraging activity
relative to urban colonies. Activity also varied among ants with different
behavioral roles - workers that were foraging were more exploratory than
workers taken from the nest or that were engaged in a defensive role
(i.e., recruited to the location of a different colony). Finally, we
identified a potential proximate mechanism that might be influencing
activity. Treatment with the hormone octopamine led to increased levels of
individual exploration and colony-level foraging activity for colonies
from both habitat types. However, natural variation in worker octopamine
levels did not vary between environments. Together, these results suggest
that exploratory behavior may play a role in adaptation to urbanization
and that octopamine may be a key driver for exploratory and foraging
behavior in odorous house ants.