Husband purchased two large rock lobster tails that were frozen at our local restaurant. Cooked after thawing that evening and both he and I took one bite and it was as if there was an explosion of ammonia in our mouths so we spit out what we had not already swallowed. I am immediately researched and learned that the lobster were dead at the time of being caught and that this is essentially their bodies decomposing breaking down into high ammonia levels. I am a nurse and recognized the next day when I experienced severe painful diarrhea and my husband experience nausea, confusion and dizziness that these were signs of high ammonia levels in our bodies which can damage the kidneys, produce all of these symptoms, can cause coma, and even death. It is always best to cook your lobster live. Lesson learned and thank God our symptoms were not worse. Be warned and be aware.