A 10 gallon tank would be too big for many species of tarantulas. In many cases it is too tall. One way to correct this is to add a lot of substrate so that from the top of the tank to the top of the substrate it isn't more then 1 1/2 times the leg span of the tarantula. If not the tarantula can fall if it climbs to the top of the tank and it can rupture it's abdomen, in which case it will died. This many not look that appealing to most people looking at a tank full of substrate but if the tarantula tunnels it is pretty cool but it is for the safety of the animal. You can also turn the tank on it's side and use it for arboreal species of tarantulas. Let me add (just in case) that only one tarantula should be housed in a cage.
You can do a planted terrarium with live plants with one to two emperor scorpions. There are some species of scorpions that are communally and so that are not.
Another option that I'm surprise that no one has suggested is the viper gecko or sand geckos. You can have a few in a 10 gallon tank. Then do a backing like Vicious Fish did with his leopards and they would have multiple levels to climb on.
You can do a planted terrarium with live plants with one to two emperor scorpions. There are some species of scorpions that are communally and so that are not.
Another option that I'm surprise that no one has suggested is the viper gecko or sand geckos. You can have a few in a 10 gallon tank. Then do a backing like Vicious Fish did with his leopards and they would have multiple levels to climb on.
