Spontaneous and triggered pulsing behavior in InGaAs multiquantum well devices driven by a constant bias voltage are reported. Bias regions for the occurrence of spontaneous periodic oscillations as well as damped triggered pulsing were experimentally determined. An empirical model based on the observed shape of the I-V curve and the negative differential conductance is proposed to qualitatively explain both the triggered pulsing and the spontaneous oscillating behavior, which could lead to novel infrared detection techniques and neural network applications.