Caenorhabditis elegans uses eleven chemosensory neuron pairs to respond to changes in its environment. Feeding state often modulates the olfactory response, and can induce adaptation, sensitization, or cross-saturation. Starvation produces adaptation and enhanced olfactory discrimination, while well-fed states can produce cross-saturation between odorants detected by the same neuron. Osm-9, a transient receptor vanilloid protein, has been implicated in C. elegans’ ability to sense its feeding state and is essential for adaptation to isoamyl alcohol. Isoamyl alcohol and benzaldehyde are volatile odorants detected by the AWC neuron, and can cross-saturate in a well-fed state. To determine the role of osm-9 in feeding states and in olfactory adaptation and cross-saturation, adaptation and cross-saturation assays were conducted using a wildtype strains, an osm-9 loss-of-function mutant, and a strain with loss of function in its AWA neuron pair. Olfactory responses during different feeding states were observed, and RNA samples were extracted at different stages of each procedure. Real-time PCR was used to quantify the expression of osm-9 at different feeding states and during olfactory adaptation in order to determine its role in modulating C. elegans olfaction.