You kill one more spider, and the last four attack.7

(1d20+5)[17] - [1]+poison - (1d2)[2] Str damage (Fort DC 10 negates)
(1d20+5)[21] - [1]+poison - (1d2)[1] Str damage (Fort DC 10 negates)
(1d20+5)[19] - [1]+poison - (1d2)[2] Str damage (Fort DC 10 negates)
(1d20+5)[10] - [1]+poison - (1d2)[1] Str damage (Fort DC 10 negates)