PT  - JOURNAL ARTICLE
AU  - Ryan W. Draft
AU  - Matthew R. McGill
AU  - Vikrant Kapoor
AU  - Venkatesh N. Murthy
TI  - Carpenter ants use diverse antennae sampling strategies to track odor trails
AID  - 10.1101/327379
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 327379
4099  - http://biorxiv.org/content/early/2018/05/21/327379.short
4100  - http://biorxiv.org/content/early/2018/05/21/327379.full
AB  - Directed and meaningful animal behavior depends on the ability to sense key features in the environment. Among the different environmental signals, olfactory cues are critically important for foraging, navigation, and social communication in many species, including ants. Ants use their two antennae to explore the olfactory world, but how they do so remains largely unknown. In this study, we use high resolution videography to characterize the antennae dynamics of carpenter ants (Camponotus pennsylvanicus). Antennae are highly active during both tracking and exploratory behavior. When tracking, ants used several distinct behavioral strategies with stereotyped antennae sampling patterns (which we call sinusoidal behavior, probing, and trail following). In all behaviors, left and right antennae movements were anti-correlated, and tracking ants exhibited biases in the use of left vs right antenna to sample the odor trail. These results suggest non-redundant roles for the two antennae. In one of the behavioral modules (trail following), ants used both antennae to detect trail edges and direct subsequent turns, suggesting a specialized form of tropotaxis. Lastly, removal of an antenna resulted not only in less accurate tracking but also in changes in the sampling pattern of the remaining antenna. Our quantitative characterization of odor trail tracking lays a foundation to build better models of olfactory sensory processing and sensorimotor behavior in terrestrial insects.Summary Statement High resolution imaging of antennae reveals distinct patterns of sampling with non-redundant roles in odor tracking.