We found a small insect on our window and we cannot decide whether it is a type of grasshopper or grass beetle. It doesn't seem to want to fly, but was on a first floor bedroom window, and walks slowly and has a strong grip on the window and petri dish. We live on the outskirts of a town in Essex, UK and it could have come from a field, but they are on the other side of the house. It is a small brown insect (the main body is approximately 2cm long) with 6 legs, and the back 2 legs seem to bigger than the others.
Neither beetle nor grasshopper, it is a hemipteran, Coreidae. Leptoglossus occidentalis or Western Conifer Seed Bug. https://www.britishbugs.org.uk/heteroptera/Coreidae/leptoglossus_occidentalis.html