Sick young ants release a smell to tell worker ants to destroy them to protect the colony from infection, scientists said Tuesday, adding that queens do not seem to commit this act of self-sacrifice.Many animals conceal illness for social reasons....

You must have noticed this common thing in your home, office, or even shops — most ceiling fans have only three blades. While four- or five-blade fans also exist, they are less common in India. Engineers and manufacturers say there are strong scientific and...