Cockroach inside the class 100 room

[Jianhao Shen]

Hi professor,

We found the source of the cockroach inside the class 100 room. It's the tube under the spin coater. We don't know what that tube is for. But we have to cover the end tightly to prevent them keep coming out. Please let us know what to do next. Thanks. 

Best regards,
Jianhao Shen

[Andrew Sarangan]

That tube was the drain tube from the spray developer (which I took out for repairs). Can you pour some water down that line to flush it out? It's probably been dry for too long, and that might be the cause.