Octanol avoidance behavior is highly conserved in nematodes and is mediated by ASH neurons. Most species had similar avoidance times to Caenorhabditis elegans. Panagrellus redivivus showed significantly higher avoidance time to 100% octanol than Caenorhabditis elegans. ASH neuron ablations in different species resulted in animals not sensing 100% octanol. A mutant defective in the C. elegans vesicular glutamate transporter eat-4 was used as a negative control . Data are represented as mean avoidance time (in seconds) and error bars indicate standard error of mean (s.e.m). Mean avoidance time of different species was compared by ANOVA. Presence and absence of neurons is denoted by '+' and '-' respectively. P values are denoted as follows: ***, P < 0.0001. For unablated and ablated conditions, n = 30 and n = 15 animals, respectively.