The hospital was looking like a clear lake
A lotta preying/praying invertebrate
Lil B is directly comparing a hospital to a lake. A Hospital is full of immobilized/paralyzed (invertebrates are spineless) people who are praying for divine help. A lake is full of invertebrates (the aforementioned spineless creatures) preying on their potential food. Two different perspectives of praying invertebrate vs. preying invertebrate.
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