Overlabbing is the third part of the first aired and the second produced episode in season 4 of Dexter's Laboratory, which first aired on November 22, 2002. In this episode, Dexter and Mandark go underground to expand their laboratories. However, when they agree to share their labs, chaos ensues.
Dexter and Mandark are going to extend their laboratory sizes to make room for more of their inventions but when they do, they both overlap their laboratories into each others without noticing. Once they figure out, they get into a fight which is too evenly matched and the two of them are now forced to share.
They both start working on plans. Mandark's plans are to destroy Dexter's Lab and Dexter's Plans are to keep Mandark from destroying his lab. They both start critisizing each other's plans and then they both remodel each other's sides of the laboratory and completely change it into their own ways. Then, Dexter and Mandark destroy each other's labs and cause a huge hole in the ground destroying the neighborhood above causing chaos everywhere and they both argue over who won.