How can you survive a bomb?

Answer 1

That depends on how intense the fallout was, the radiation LD50 for that type of creature, and whether they have a place to shield them from some of the radiation from the fallout.

Insects and other simple creatures have much higher radiation LD50 than mammals and other complex creatures.

Small creatures that often live underground will have some shielding.

However if the fallout is very intense at a given location almost nothing except perhaps bacteria will survive (if even that)!

Humans can survive if they have a fallout shelter to live it that will shield them, a positive pressure forced air HEPA air filtration system to maintain fresh air in the shelter while preventing fallout from entering with the air, and at least one wide range ionization radiation survey meter to check both inside and outside radiation levels to check for contamination of the shelter and to determine how long it is safe to go outside should that be necessary. Other creatures do not have the advantage of being able to build and/or learn to use these tools to protect themselves, like humans do.

Answer 2

>95% of life on earth. Deep subterranean bacteria.

Answer 3

Bomb shelters were used in both England and Germany during WW2 to protect people from the blast and shrapnel of explosive gravity bombs. They worked very well.