Unlike us humans who have a breathing reflex, dolphins have to remain conscious even when they are sleeping. To get around this, dolphins only allow one half of their brains to sleep at a time; the other half stays alert to enable the dolphin to continue breathing and look out for dangers in the environment. This is called unihemispheric slow wave sleep (USWS), and it's found in marine mammals such as whales, dolphins, fur seals, and sea lions. Some birds have even more amazing capability to switch between sleeping with both hemispheres to one hemisphere.

Highly social insects show intervals of activity around the clock in several different contexts. In contrast to most insects, newly emerged honeybees and bumblebees typically have no circadian rhythms in locomotion or metabolic activity. Endogenous circadian rhythms appear only later in life. Understanding the mechanisms behind this may enable us to better control our internal clock, and turn it on or off as we need it.

Planarians are flatworms found in freshwater bodies and their regenerative abilities have been documented for centuries. Planarians can regenerate new heads, tails, sides, or entire organisms from small body fragments in a process taking days to weeks. Regeneration in planarians depends on the presence of stem cells called neoblasts. These cells are distributed throughout the body and, when part of the worm has been amputated, they are activated to reform the tissues that have been removed.

Absorbed doses of radiation are measured in Grays and ten of these are more than enough to kill a human. In comparison, two species of bdelloids survived as much as 1,000 Grays and were still active two weeks after exposure. Their children also didn't show ill effects due to the radiation. These figures make the bdelloids the most radiation-resistant of all animals so far tested. Even other rotifer groups show similar levels of sterilization at a fifth of the doses tolerated by bdelloids.

If you are a Marvel fan like us, you may remember this impossibly cute creature that showed up in the Antman movie, as Scott Lang shrunk in size and dived into the quantum realm. In fact, tardigrades, a.k.a. water bears or moss piglets, are known to be able to live for up to 30 years without food or water. They can endure temperatures of up to 150 degrees Celsius, the deep sea, and the frozen vacuum of space. They are also almost as good as rotifers at withstanding radiation.

Radiotrophic fungi were discovered in 1991 growing inside and around the Chernobyl Nuclear Power Plant. An experiment taking place at the International Space Station from December 2018 through January 2019 was conducted in order to test whether the use of radiotrophic fungi could aid in protection against ionizing radiation in space. The growth of fungus and its ability to deflect the effects of ionizing radiation were studied for 30 days aboard the International Space Station. This experimental trial yielded very promising results.

While it's hard to fight microgravity directly, what if we get a higher bone density in the beginning? Many mammals such as rats have higher bone density than humans, which means the loss of bone density will not influence them as much. One theory is that these mammals were able to generate some kind of hormones to stimulate bone density growth. If we can find out the reason behind our differences, we may be able to use such chemicals to keep our body balanced a suitable level.