I have a php script that has the ability to generate web analytics from several websites, all from a unique server.
The tacking code is javascript based, something like:

<script type="text/javascript">..jscode..</script>
<noscript><image to track users with disabled javascript></noscript>

I've noticed some traffic is not caught by code above (I've used php to generate a raw log of local traffic), some are clearly bot traffic, but others left me in doubt, so, my question is:
Is it possible the users not being tracked by the js/noscript code are genuine human users or just bots/automated traffic?