ID this bug for me please.

Looks like something we have in South Africa called Rysmiere. Some native people eat them. Apparently they taste like butter.
Have not had the need to try them myself yet....lol

https://www.google.com/search?client=safari&channel=iphone_bm&ei=rOP6WOGvBdLMjwOj-IP4Bg&q=rysmiere&oq=rys+mier&gs_l=mobile-gws-serp.1.0.0i10k1l5.5746.14974.0.16401.27.21.5.1.1.0.420.3721.0j17j2j1j1.21.0....0...1c.1.64.mobile-gws-serp..9.18.1783.3..0j41j0i131k1j0i67k1j0i70k1j33i160k1.x29yVnmtt28

What you had was a hatch, and having them come out from where they did means that particular batch had nothing to do with your house.  Most locals in Cal are infested with termites, just a natural thing.  Every place in my neighborhood  where wood touches the ground will be full of them.

I had a hatch like that inside my house, came home from work (in the 80s) and the whole house was full of thousands of them. Over the years I've had lots of experience with termites, subterranean and dry wood.

I'd seriously get a reputable termite inspection co. to come out and do an inspection, might stop an ongoing infestation or at least give you peace of mind. 

Subterranean termites need to be able to get to moisture every day and are usually very effectively gotten rid of by treating the ground around the foundation and under the house.

Dry wood termites live in the wood and never come out and can only be effectively killed by tenting, which seems like it wouldn't work (once you see it) but worked well for us.

Treating the ground won't kill dry wood termites and tenting will only kill whatever's in the wood at the time so not too effective for subterranean

Get an inspection, get references for the inspector first, peace of mind or finding a real problem now rather than later.