Do all living things have a heart?

[Julie]

do all living things have hearts. eg. ants,worms and things like that

[andy hughes]

No. Only organisms with complex circulatory systems require a heart to pump blood around their bodies. Many orgaisms with simple systems live without a heart, including ants and worms. Stand by - my learned Incitatus will provide a far more detailed and accurate answer - he'll be along in a minute.

[incitatus]

Cheeky. You mainly have it covered. All multicellular organisms need to induce nutrient flow, but not all have a heart. Segmented worms tend to have a microheart in each section. Insects and arachnids do not have either heart or lungs, relying on body movements and transpiration instead. many molluscs have compicated valving arrangements instead. All higher organisms (as they used to be called) do have a heart of some kind, though. So mammals, reptiles, birds fish etc. all do