diff --git a/src/population.rs b/src/population.rs
index dad61f7..328de34 100644
--- a/src/population.rs
+++ b/src/population.rs
@@ -151,11 +151,11 @@ impl Population {
             //now we can start to check if people would be infected or not
             //let idx = human_idx(pos.x as i32, pos.y as i32, self.width as i32);
             if pos.x > 0 && pos.x < self.width - 1 && pos.y > 0 && pos.y < self.height - 1 {
-                if Population::roll(self.plague.curing_rate) {
+                if roll(self.plague.curing_rate) {
                     //checks if the man recovers
                     people_to_cure.push(Point { x: pos.x, y: pos.y });
                 } else {
-                    if Population::roll(self.plague.death_rate) {
+                    if roll(self.plague.death_rate) {
                         //cheks if the man dies
                         println!("someone should die");
                         people_to_kill.push(Point { x: pos.x, y: pos.y });
@@ -204,7 +204,7 @@ impl Population {
                             let inf_idx =
                                 human_idx(poss_infected_pos.x, poss_infected_pos.y, self.width);
                             if self.humans[inf_idx].present_state == State::Normal {
-                                if Population::roll(self.plague.infection_rate) {
+                                if roll(self.plague.infection_rate) {
                                     people_to_infect.push(Point {
                                         x: poss_infected_pos.x,
                                         y: poss_infected_pos.y,
@@ -293,10 +293,7 @@ impl Population {
         }
         stats
     }
-    pub fn roll(probability: u32) -> bool {
-        let mut rng = rand::thread_rng();
-        rng.gen_range(0..CORRECTED_PERCENTAGE) <= probability as i32
-    }
+
     // pub fn display(&mut self){
     //     let sprite = "#";
     //     print!("\n");
@@ -316,6 +313,11 @@ impl Population {
     // }
 }
 
+pub fn roll(probability: u32) -> bool {
+    let mut rng = rand::thread_rng();
+    rng.gen_range(0..CORRECTED_PERCENTAGE) <= probability as i32
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -431,7 +433,7 @@ mod tests {
         let tries = 1000;
         let mut result = 0;
         for _x in 0..1000 {
-            if Population::roll(rate) == expected {
+            if roll(rate) == expected {
                 result += 1;
             }
         }