How does JMS Queue decide which listener will receive a particular message?

How does JMS Queue decide which listener will receive a particular message?

I have a program that has about 500 messages going to a JMS Queue. Then I
have 3 other programs all listening to the same queue. The interesting
thing is, if i start one listener and then run the program to send all the
messages and then wait until the listener receives 50 of them and then
start the other two listeners, each of the latter two listeners only
receive one message and then stop, while the first listener receives the
other 498. Why does this happen? And what can I do to fix it? If its
relevant, the broker is running on a Glassfish server.