Well hi there Sealrescueuk!
I found a couple of websites for you that have plans for making your own bat boxes and ladybird (otherwise known as ladybug) boxes.
Bat: www.tvwc.org/index.htm click under updates: building nest box for microbats.
Of course there are all kinds of places on line to buy them already made too.
Hope this helps! Feel free to ask any questions - that's what it's all about!