Memory is usually related to higher organisms. However, a recent study conducted by scientists at the University of Texas at Austin has found that despite the lack of neurons, synapses, and nervous systems, when millions of bacteria gather on the same surface, they can form things similar to memory, such as how to swim together, when to form biofilms, etc. Moreover, bacteria can at least pass on these "memories" to their "great grandchildren.". Further analysis shows that seemingly ordinary iron is the mastermind behind the formation of this "memory" by bacteria. The relevant paper is published in the Journal of the National Academy of Sciences in the United States. So, can bacteria really form "memories" and pass them on to offspring? Fu Yu, a researcher of the State Key Laboratory for Early Development of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, told Science and Technology Daily: "Strictly speaking, the bacterial 'memory' elucidated by scientists at the University of Texas at Austin is not a biological memory, but a response of bacteria to external stimuli based on changes in iron concentration. This enables bacteria to survive and reproduce better in complex environments." "The latest research has enlightening significance for us to deal with bacterial resistance. For example, we can artificially regulate the concentration of iron to reduce bacterial attachment to the infected site, reduce bacterial resistance to antibiotics, facilitate the immune system to clear pathogenic bacteria, and enhance the efficacy of antibiotics." Fu Yu further emphasized. Iron is one of the behind the scenes heroes. Higher animals, including humans, have the ability to remember, which enables them to constantly adapt to changes in their environment and quickly respond correctly. Research shows that this memory ability originates from neural tissue. After receiving external stimuli, neural tissue will form neural impulses, which form conditioned reflexes to specific stimuli and can respond accordingly when encountering the same stimuli in the future. Fu Yu introduced, "Although bacteria do not have a brain and cannot remember information like higher animals, they do have a 'memory' mechanism in a sense. This mechanism is mainly reflected in their adaptability to environmental changes, as well as their transmission of genetic information and chemicals. Bacteria can collect information from the environment.". If they frequently encounter this environment, they can store information and quickly access it in the future, which is beneficial for them. The latest research conducted by a team led by scientist Suvik Batacharia from the University of Texas at Austin has found that bacteria can not only form "memories" but also pass them on to their offspring. Scientists have previously observed that bacteria with experience of swarm movement (rapid movement of numerous bacteria driven by flagella) are more willing and capable of moving in groups. Batacharia and others hope to clarify the underlying reasons for this phenomenon. To this end, they designed an experimental device that can monitor the clustering movement of over 10000 Escherichia coli cells. A series of analysis results show that these Escherichia coli can retain the "memory" that forms cluster movement for at least four generations, which is passed on to their "great grandchildren", and will not completely disappear until the seventh generation. So, how is this "memory" preserved and transmitted? The answer points to iron. Iron is the earth