Tree frogs

[val douest]

There are a lot of these attractive bright green frogs in our garden but they are usually heard (a very loud noise for such a small creature) rather than seen. However, a whole colony of them has taken up residence in the housing of the swimming pool pump. I think they get in to the pool through very small spaces under the abri and then climb out of the skimmer basket onto the area beneath the cover, where they are trapped (though they may like the dark damp space). The first couple of mornings I painstakingly transferred them all to some wet grass under the hedge some distance away but next day they were back - this morning there were six of them! I can't think it is very good for them to be in chlorinated water, even briefly. Any suggestions as to what to do to encourage them to take up residence somewhere more conducive to their health? And what will happen to them in the winter - do they hibernate, and if so, where? In the pump housing maybe?

Any information appreciated,

Val