Help! What are these bugs / mites?

Eldi_Dos

If you can leave your house for a few hours I would be tempted to treat your en suite as a greenhouse and get one of those smoke cones used to fumigate greenhouses. En suite would need to be well sealed up and when you came back to the house ventilate and open all the windows room by room until you reach en suite then put on extractor fan without opening door.
Make sure all the house is well ventilated before closing any windows.

Edit. 
If en suite is not used on regular basis are all the U bends and shower traps working as they should and not dried out.
Putting some bleach down them might help in case the bugs are using them for water.

boots_babe

Eldi_Dos said:

If you can leave your house for a few hours I would be tempted to treat your en suite as a greenhouse and get one of those smoke cones used to fumigate greenhouses. En suite would need to be well sealed up and when you came back to the house ventilate and open all the windows room by room until you reach en suite then put on extractor fan without opening door.
Make sure all the house is well ventilated before closing any windows.

Edit. 
If en suite is not used on regular basis are all the U bends and shower traps working as they should and not dried out.
Putting some bleach down them might help in case the bugs are using them for water.

Thanks for the suggestion.  Have never heard of those so have just googled,  do you mean something like this?

Vitax Greenhouse Fumigator https://amzn.eu/d/4Sc6DjA

We have 3 cats so would need to get them to the cattery for a couple of days, and will need to check the safety aspects, especially for them when they come back to the house.

Eldi_Dos

Yeah something along those lines. As you say you really have to think of the safety aspects first, but generations of gardeners have been using similar, then growing crops in greenhouse.

Have you checked U bends and shower drain are working as they should, as it could be something as simple as that.

Albermarle

boots_babe said:

We found a steam cleaner and used this to thoroughly go over everything.  Less than 2 hours later they were back :-(

How about cleaning them all away again, but this time stay in the bathroom to see if you can spot where they are coming from ?

boots_babe

Good idea, will try that. 

prettyandfluffy

Some years ago I got rid of bed bugs by using Acclaim household flea spray.  It is highly toxic so take great care if you use it but it does seem to kill most creepy crawlies.  ETA You can buy it online.