STL question: Is it necessary to delete an object from std::list

[Miran]

Thanks all for the answers.
I'm sorry but I still have a question.
Let we have following situation.
As wrote Paul McKenzie we add objects to the list, not a pointers:

#include <list>
std::list<MYSTRUCT> g_MyStructList;
//...
int main()
{
   MYSTRUCT m;
   g_MyStructList.push_front( m );
   // No need for delete
   // ...
}

Since the object m was defined in main function it becomes not valid out of the scope of main. Let MyFunction is called from another thread. What will be if I want to get the object from global g_MyStructList list?
The synchronization of access the same global list from different threads is out of the scope of my question. I just want to know: Is *itr a valid MYSTRUCT object or it does not?

void MyFunction() // called from different thread
{
   std::list<MYSTRUCT>::iterator itr = g_MyStructList.begin();
   // Is *itr a valid MYSTRUCT object?
   // .....
}

Thank you.