In Laravel Observer Not tracking eloquent event like created,updated,deleted

I have on model User in that i am insert record bulk but observer not working in these scenario it will not detect it's create,update,delete event but if i use create it's work perfectly any other work around also accepted. If any one help in these scenario it will be highly appreciate.

Model App/User.php

$raw_data = [
    [
        'name' => 'stackoverflow'
    ],
    [
        'name' => 'stackoverflow1'
    ],

];

User::insert($raw_data);

via Chebli Mohamed