how to use pfsense for cloud plumbing ( detecting new instances) in VPC-AWS

Hi all,

I created a VPC inside AWS and I have put pfsense as software router inside it. I get that normally ( outside aws environment) Pfsense works with DNS and DHCP protocol when it detects a new machine inside the subnet to give and get the IP address of that new machine.

Instead in AWS, the DHCP is done automatically by Amazon. so my question is how can Pfsense detect a new instance inside a VPC?

Thanks very much for your answers!