Need help with mystery noise

[russp]

A very small pistol can make a very big noise , I was running a canister filter when I first started my tank & one day when cleaning the filter I came across a pistol shrimp that was about 3/8 -1/2 of an inch . I put him in a 10gal that I have set up & ever since the snapping started in that tank too , & it is loud enough to be heard all through the house at night. Also turbo snails can make a very similar noise by spinning there shells back & forth quickly & hitting the glass . I have witnessed this a number of times.