Only bees have 5 chambers in their heart. All other species have lesser chambers in their hearts. Human heart has 4 chambers: 2 atria and 2 ventricles. Bees have an open circulation system, unlike us. In such a system, the blood is not enclosed within vessels or tubes, rather it is everywhere inside the body. The heart of a bee is a simple structure and consist of musculated chambers and 5 pairs of openings. The dilation of heart forces the blood into the heart, while its contraction forces the blood to the aorta.
The 5 chambered heart is the rarest of rare occurrences in human beings and is a congenital cardiac defect called Cor triatriatum. Recently an infant boy, in Russia, was reported to have 5 chambers in his heart. Another case has been reported in Nigeria. A human being with a 5 chambered heart is also called as a "bee-baby".
Hope this helps.