Mathematical modeling of growth and thermal inactivation of microbial population in foods systems is a widely used technique in food safety for predicting populations of bacteria over time under different conditions of the growth media including pH, temperature and water activity. This enables food processors to design their processing and storage operations for optimal performance while ensuring safety of the food throughout the processing, storage and retail chain. Most of these models are designed for static conditions, but in the past several years dynamic models have been developed which can predict growth and inactivation of bacterial populations in dynamic conditions of the growth media including fluctuating temperatures, which makes them more practical and easy to apply in real-life situations. This presentation would present some of these static and dynamic models for bacteria, and also demonstrate their applications in the area of thermal inactivation of insect pests. Important issues like the time-lag exhibited by insect populations in response to heat-treatment would also be covered along with some ideas on how the ‘lag’ can be modeled as well to increase the predictive ability of dynamic thermal inactivation models for insect pests.