Yes they can get stuck in things,especially rigid toys with holes that aren't big enough. For a syrian the hole would need to be a diameter of 6cm. A small syrian may get away with 5cm diameter but I wouldn't risk it. 6cm minimum really. If they have full pouches they can be as wide as almost 7cm. If it's a wood toy you can block off any holes that are too small by glueing a small piece of wood over them (using something like elmer's school glue which is safe to use). If it's ceramic - I wouldn't get a ceramic house with holes that aren't big enough really