just to add, a normal desk lamp (i use the £2.99 ones from argos) fitted with a high watt bulb (also pretty inexpensive) is a great source of both cheap heat and light, and is a bit more variable than a heating solution involing a heatmat, as heatmats only reach a set temp as far as im aware, while with bulbs you can adjust how much temp each mantis gets by how far from the bulb it is for example. also heating from below heats the whole enclosure evenly, and doesnt give the mantis a choice, whereas a bulb can shine brightest/warmest in a certain place, and less so in other places, giving the mantis a choice (sometimes you see them purposely basking in the warmest cone of the bulb, sometimes in a cooler area). a nice bright bulb will also heat a wider area than an equivalent heatmat (i.e to match the heated area of a bulb you would probably need a fiarly large heatmat, which would cost you alot more than lamp and bulb). not that any of this is necessary or all that important, i'm just stating the advantages i've experienced.