This nest building behavior is instinctual for male bettas and it is not necessary to have a female present to observe your betta building his nest. Most males will blow bubbles but the rate and size of the nest seems to depend on the individual male and possibly, other factors like age, health and water parameters.
Berlin was always the centerpiece of the Cold War and, more often than many remember, very nearly the front line of real combat. At the end of World War II, the city was divided into four sectors, each occupied by one of the four allied armiesâU.S., Soviet, British, and French.
The United States and the Allies were left with no choice but the Berlin Airlift. They could force their way into the city, but it would likely lead to a full blown conflict with the Soviet Union. However they also didnât want Stalin to gain total control of the city.