Worldwide, feral cats (Felis catus) have contributed to some of the greatest biodiversity losses, and are listed as one of the worst invasive species. This is particularly evident in New Zealand where native fauna evolved without mammalian predators. Feral cats are predators of native species and are sometimes the focus of control operations. Knowledge of their activity patterns and home range can be used in pest management by indicating the best time for capture, and spacing of traps. We studied a population of feral cats on Ponui Island, New Zealand. Nine adult cats (6 male, 3 female) were live-trapped and fitted with radio transmitters from April 2015 to January 2017. Twenty eight motion-sensing cameras were also set up in a grid over the site to monitor cat movements and activity. Males had larger home ranges than females and showed greater home range overlap then females. Feral cats were most active at night, with a peak of activity in the first hour of darkness. The worst time for capturing was between 07:00-11:00 where cats were least active. Literature indicates that the home range size of feral cats tends to decrease linearly with increasing density. We tested this relationship by manipulating the density of the cat population by removing cats. This resulted in an increase in home range by one cat (first manipulation), and an invasion of cats (second manipulation). This knowledge will help customise management plans to better control these pests and reduce their damage to native fauna populations.