Organism monitoring devices and organism monitoring methods are described. According to one aspect, an organism monitoring device includes a housing configured to be physically associated with an organism to be monitored, an antenna, signal generation circuitry comprising an oscillator configured to generate an oscillation signal, and an output node configured to output the oscillation signal, impedance matching circuitry coupled with the housing, the antenna and the signal generation circuitry, and wherein the impedance matching circuitry is configured to match an impedance of the signal generation circuitry and an impedance of the antenna, and wherein the impedance matching circuitry is further configured to receive the oscillation signal and to provide the oscillation signal to the antenna, and wherein the antenna is configured to emit a wireless signal externally of the organism monitoring device as a result of the provision of the oscillation signal to the input of the antenna.