Housing local snails together-help appreciated!

[han]

Hi there.  I'm hoping someone would be able to give a bit of advice. Apologies in advance, I've only recently been learning about snails.

My snail obsessed son has recently asked to keep four snails as his pets.  He has found 2 white lipped (Cepaea hortensis), a strawberry snail (Trochulus striolatus) and a Girdled snail (Hygromia cinctella). We have researched how to keep them happy and bought substrate and calcium for the little guys.  Currently we've got the white lipped snails in a separate tank to the other two much smaller snails but I was wondering if we can put them all in together and will they be happy or will we be creating a sort of snail Thunderdome? My son is very young and I think his beloved snaily mates eating each other might lead to a few issues down the road.
Also if your snails have mites is it very obvious?  I read that mites could kill smaller snails very quickly.  When he first found the white lipped snails I thought i saw something small and white scutter over it's skin.  I washed it and have checked every day but haven't seen anything since (not 100% it was there in the first place!).  That was two weeks ago. If they had the bad mites would they be crawling with them by now?

Any advice would be massively appreciated!  Thank you!

 

[simple]

Oh no. A single white mite is enough to have an infestation. If you've seen one outside, there are likely many more hiding inside the snail's pneumostome, and they spread to other snails like the plague. If they are indeed Riccardoella limacum, the white snail mite, your only way out is to buy predatory mites.

About the size difference, I keep Theba pisana and Cornu aspersum on the same terrarium with no problems, but it's always better to be safe than sorry! Whether you should or not is up to you and your son.

[han]

Thanks so much for getting back to me!
Sorry if this is a daft question but if we put them in together and get predatory mites will the mites hurt the smaller snails? I know the mites are tiny but the strawberry and girdled snails are both only about a centimetre (shell size).

[simple]

You're welcome! 
No need to worry about the predatory mites eating the snails, they only eat things that are either the same size or smaller and they are just half a millimeter.

[han]

Brilliant. They'll all be getting some mite buddies then.
Thanks again for the advice!