There was an incident at the Venezuela expedition which I can't get out of my head: a frog expert was totally surprised how dry the soil was where his favourite animals (Dendrobates leucomelas) were hopping around. Time and again we read terms, such as humid, semi-humid or dry, about the soil quality of terrariums. But how much is this really in percentages or in another measurable and therefore comparable measuring unit? For our next expedition to Madagascar and to other islands in the Indian Ocean in October 2018 I would like to take along a measuring device to measure soil moisture. A quick glimpse into the internet shows that there are a lot of measuring devices but there were also many critical remarks about these devices. Can anyone give us a tip about an affordable measuring device which isn’t too large, because luggage is always our biggest problem?