| Under polite questioning from the audience, he acknowledged that some closed-source commercial products have been found to have trapdoors themselves. |
| They would then open the trapdoors to allow the hurrier and his cargo through. |
| Meet the trapdoor spiders, famed for their silk-lined burrows complete with emergency exits, hinged trapdoors and careful camouflage. |
| The trappers also opened the trapdoors to provide ventilation in some locations. |
| The trapdoors are made of soil, often clay, modeled into shape and reinforced with silk. |
| Both sides of the hall were lined with doors and even the ceiling had trapdoors spaced at periodic intervals in it. |
