Fencing - HELP!

Currently my two AQH geldings are sharing a pasture with my niece's mare. For weeks now they've been considered Houdini's in the Making. I've found them all over the place - in the driveway, in my neighbor's fields. It's pretty scary, waking up and finding them who knows where. I'm concerned that one day they'll wander out to the road or get seriously hurt jumping the barbed wire my neighbors have recently put up. I've tried several types of fencing, from electric to wooden railing, yet nothing seems to work. Here are my two questions.

1) Will my niece's mare develop bad habits because of these two escape artists?

2) What's a good, sturdy type of fencing?

I've found my fences torn down, cribbed at, and somehow unlocked. HELP!

Have you figured out HOW they are getting out? That would be the first thing to investigate. Have you or anybody home been observing to see what they are up too?

Once you have any Idea to what/when and how, you may be able to simply reinforce and/or change your gate-lock system to stop this behavior. As to teaching others the tricks of the trade, I not convinced they are passing secrets to one another. I've witnessed it's normally one bored equine that spends the efforts at this pastime. Detective work will also reveal which one(s) are the culprits...

If they are destroying older or damaged parts of the fencing ( I assume it's wood?) simply inspecting the surrounding wood for loose or weakened parts and replacing/fixing should be the cheapest way to deter this...The idea is don't let it be simple for them to get away with it..
One more pretty bullet-proof yet not real cheap method of fencing is the heavy plastic railing.It isn't easy to break, and it doesn't require any maintenance. The stronger the in-ground posts, and the closer together they are, the stronger they will be...provided you don't have any "jumping over" Issues..

Good luck

Well, I work from 8:30am to four thirty Mond-Sat. I usually turn them out into the pasture before I go to work every morning, and bring them in when I return. I don't have much time to inspect damage, but tomorrow I will try to get out there and take a good look around. Also, I'll ask if a friend of mine will watch them on Monday. I'll get back to you with what she finds.

( I have also added more stuff to my original reply..sorry)

One more idea that may be of help, is can you video-tape the paddock?
Do you have a video cam? It may have an "extended record" option, just having enough battery or other power to keep it running will be needed. Or if you have an older model VCR, they sometimes have a "very long play" or "super long play", I can't remember which it's called anymore,but you should be able to plug a video cam into it, select the longest record time, set it up out of the weather, experiment with the recorded view, and you may be able to figure it out that way...

I'm a photographer by trade, so I do stuff like that all the time..it's the way I think.. I don't know that's an option for you though...