Neuroethology is the study of neural basis of natural behavior. I studied learning using sound as a cue in fruit flies and made recordings from the Johnston's organ (JO), I also investigated associative learning in mosquitoes. Finally, I studied Salticid (jumping) spiders to investigate the neural basis of their visual behavior, as well as their acoustic behavior. These three lines of research provided opportunities to learn about ecologically relevant behavior of arthropod models and to learn electrophysiological tools to integrate the study of neural function in behavior. In terms of the application of these studies, my work on conditioning fruit flies to associate sound may be useful for performing behavioral screens of hearing mutations. Applying the method of bulk conditioning to mosquitoes might be a useful technique for screening "smart" transgenic mosquitoes. Recording from neurons in the central nervous system (CNS) of jumping spiders has never been done, and I plan to share the tools that I developed as well as our new findings (hearing and vision with jumping spider) to benefit the community of researchers who are interested in these fascinating spiders. In the spider work, I have greatly benefited from my collaborations with a iii talented team of graduate colleagues, each of whom has made a unique contribution to this work. iv