Layer 3 switching running PIM. Should I also run IGMP querier snooping?

[Sam Brynes]

In my opinion, no, but I want to hear from the experts. My layer 3 switch is a Cisco 3750.

If I'm running PIM, by default, will the layer 3 switch send out general membership queries already?

AFAIK, IGMP querier snooping only sends out general membership queries if there is not a multicast router already sending general membership queries out on the same subnet.

[Reza Sharifi]

When you enable PIM, you also enable IGMP as well.

In your case, the 3750 is running PIM because is layer-3 device. So, the switch will send out IGMP queries to address 224.0.0.1 every 60 seconds. 

HTH