Signal and Taming

Hello,
I have 2 quick question the first being i am working on a tameable mob and it works just fine except it does not
display the usuall particcle effects above its head durining the taming process. is there any way to get that to happen.

the second question is how does one go about using the ~onSignal:[signal] triggers
what typically goes in it and what is the logic behind it


Thanks in advance
- Mittens