Invertebrates are the most diverse and abundant organisms in aquatic and terrestrial environments. Due to their key role in many ecosystems, biologist E. O. Wilson coined the phrase of invertebrates as the 'little things that run the world'. Besides their ecological importance, many invertebrates are useful to humans, whereas others are harmful to agriculture, human and veterinary health. This subject highlights invertebrate diversity and life histories as well as their key ecological and economic importance. It also includes hands-on laboratory and field studies. This subject is designed for students with career pathways in science (e.g. animal, environmental, forensic and medical sciences) as well as agriculture, environmental management and education.