This thesis explores the ecology, behavior, and sensory neurobiology of jumping spiders (Araneae: Salticidae). The first section (Chapters 1 and 2) investigates antmimicry by the jumping spider Myrmarachne formicaria. The second section (Chapter 3) takes a neuroethological approach to sound perception in the jumping spider Phidippus audax. Chapter 1 uses observations and collections from sites across France to study the relationship between mimics and co-occurring ant species. Behavioral trials also explore how individual jumping spiders and ants interact. Results from these studies suggest that M. formicaria is a general mimic of multiple ant species and that it does not positively associate with ants. Chapter 2 takes a quantitative approach to the study of locomotor mimicry by M. formicaria. It measures and compares aspects of gait and overall movement across non-mimetic jumping spiders, mimics, and multiple ant species. Against widely held beliefs, this work suggests that these ant mimics do not move on six legs. In their overall motion, however, M. formicaria do imitate ants. Chapter 3 uses behavioral trials and extracellular recordings of electrical activity from neurons in the jumping spider brain to explore responses to airborne acoustic stimuli. This work demonstrates that jumping spiders perceive airborne sound at distances far greater than previously believed possible (> 2 m).